Attorney Docket No. PK3923598
`
`PCT/KR2018/015477
`
`[DESCRIPTION]
`
`LUBRICATING OIL PUMP DEVICE
`
`[Invention Title]
`
`[Technical Field]
`
`The present
`
`invention relates to a lubricating oil pump device which supplies a
`
`lubricating oil to a variety of machines, and more particularly to a lubricating oil pump device
`
`capable of detecting and relieving a high pressure generated while a lubricating oil is supplied.
`
`[Background Art]
`
`In machines such as an injection molding machine, which injects a resin or a metal, a
`
`10
`
`lathe, or the like, it is necessary to supply a lubricating oil during an operation of a machine.
`
`Generally, in a lubricating oil pump device, a lubricating oil pump is used for supplying a
`
`lubricating oil to machines such as an injection molding machine whichinjects a resin, a metal,
`
`or the like. Generally, the lubricating oil pump includes a single piston which discharges a
`
`lubricating oil while being repetitively moved forward and backward by pressure application and
`
`15
`
`pressure relief of the lubricating oil and one outlet corresponding to the piston and supplies the
`
`lubricating oil to a lubricating oil pipe W in which a plurality of single metering valves V known
`
`as having one shot of discharge amountin a range of 0.03 to 1.5 ml are embedded in a plurality
`
`of parts correspondingthereto.
`
`Since the single metering valve V is operated by applying and relieving a pressure of a
`
`20
`
`lubricating oil and discharges the lubricating oil,
`
`it
`
`is necessary to relieve the pressure.
`
`Accordingly, a lubricating oil pump device capable of relieving a pressure is used.
`
`A conventional lubricating oil pump device capable of relieving a pressure includes a
`
`pump body in which a lubricating oil transfer path and a pressure relief path are formed, a
`
`

`

`Attorney Docket No. PK3923598
`
`PCT/KR2018/015477
`
`lubricating oil cartridge connected to the lubricating oil transfer path of the pump body, an
`
`actuator which movesa piston forward and backward, a relief valve including a shaft, a pressure
`
`sensor installed behind the relief valve, and a control portion which controls forward and
`
`backward movementof the piston. The conventional lubricating oil pump device measures a
`
`pressure at the lubricating oil transfer path in the pump body usingthe pressure sensorinstalled
`
`behind the relief valve used for adjusting a pressure.
`
`In more detail,
`
`the conventional
`
`lubricating oil pump device senses whether a maximum pressure occurs by using whether the
`
`shaft of the relief valve comes into contact with the pressure sensor.
`
`When the shaft of the relief valve comes into contact with the pressure sensor,
`
`the
`
`10
`
`pressure sensor transmits the contact of the shaft to the control portion and the control portion
`
`determines that the maximum pressure occurs in the pump body and controls the actuator to
`
`move the piston backward. Also,
`
`the piston moved backward by the actuator opens the
`
`pressure relief path in the pump body andrelieves a pressure inside the pump body.
`
`However, a pressure measuring method used by the conventional lubricating oil pump
`
`15
`
`device has a problem in which a pressure is relieved only when the relief valve is maximally
`
`moved backward by a pressure such that the shaft in the relief valve comes into contact with the
`
`pressure sensor.
`
`Thatis, there is a problem in which the piston is moved hindmost andrelieves
`
`a pressure by opening the pressure relief path only when the pressure inside the pump body
`
`reaches a maximum point.
`
`In other words, the conventional lubricating oil pump device uses a
`
`20
`
`method of using a safety relief valve which relieves a pressure only whena pressure inside the
`
`device reaches a maximum value. However, in this method, since the shaft of the relief valve
`
`used for protecting the safety of the pump at a maximally reached pressure is used while
`
`doubling as a shaft of a pressure detection sensor which controls a pressure used for each pipe
`
`

`

`Attorney Docket No. PK3923598
`
`PCT/KR2018/015477
`
`length, when the pressure detection sensor does not work,it is impossible to estimate a particular
`
`pressure at which a pressure thereinside may damage the device.
`
`In addition, when the pressure
`
`is greater than or equal
`
`to the particular pressure,
`
`it
`
`is impossible to relive the pressure
`
`thereinside.
`
`Also, due to the above problem, the pressure inside the lubricating oil pump deviceis not
`
`appropriately relieved such that the lubricating oil pump device in which a sealing function is
`
`very significant may be damaged.
`
`[Disclosure]
`
`[Technical Problem]
`
`10
`
`In machines such as an injection molding machine, which injects a resin or a metal, a
`
`lathe, or the like, it is necessary to supply a lubricating oil during an operation of a machine.
`
`Generally, in a lubricating oil pump device, a lubricating oil pump is used for supplying a
`
`lubricating oil to machines such as an injection molding machine, which injects a resin, a metal,
`
`or the like. Generally, the lubricating oil pump includes a single piston, which discharges a
`
`15
`
`lubricating oil while being repetitively moved forward and backward by pressure application and
`
`pressure relief of the lubricating oil, and one outlet corresponding to the piston, and the
`
`lubricating oil pump supplies the lubricating oil to a lubricating oil pipe W in which a plurality of
`
`single metering valves V knownas having one shot of discharge amountof in a range of 0.03 to
`
`1.5 ml are embedded in a plurality of parts corresponding thereto.
`
`20
`
`Since the single metering valve V is operated by applying and relieving a pressure of a
`
`lubricating oil and discharges the lubricating oil,
`
`it
`
`is necessary to relieve the pressure.
`
`Accordingly, a lubricating oil pump device capable of relieving a pressure is used.
`
`

`

`Attorney Docket No. PK3923598
`
`PCT/KR2018/015477
`
`A conventional lubricating oil pump device capable of relieving a pressure includes a
`
`pump body in which a lubricating oil transfer path and a pressure relief path are formed, a
`
`lubricating oil cartridge connected to the lubricating oil transfer path of the pump body, an
`
`actuator which movesa piston forward and backward, a relief valve including a shaft, a pressure
`
`sensor installed behind the relief valve, and a control portion which controls forward and
`
`backward movementof the piston. The conventional lubricating oil pump device measures a
`
`pressure at the lubricating oil transfer path in the pump body usingthe pressure sensorinstalled
`
`behind the relief valve used for adjusting a pressure.
`
`In more detail,
`
`the conventional
`
`lubricating oil pump device senses whether a maximum pressure occurs by using whether the
`
`10
`
`shaft of the relief valve comes into contact with the pressure sensor. When the shaft of the
`
`relief valve comesinto contact with the pressure sensor, the pressure sensor transmits the contact
`
`of the shaft to the control portion and the control portion determines that the maximum pressure
`
`occurs in the pump body and controls the actuator to move the piston backward. Also, in the
`
`conventional lubricating oil pump device, the piston is moved backward by the actuator such that
`
`15
`
`the pressure relief path in the pump bodyis opened and the pressure inside the pump bodyis
`
`relieved.
`
`However, a pressure measuring method used by the conventional lubricating oil pump
`
`device has a problem in which the piston is moved hindmostand relieves a pressure by opening
`
`the pressure relief path only when the relief valve is maximally moved backward by a pressure
`
`20
`
`such that the shaft in the relief valve comes into contact with the pressure sensor, that is, the
`
`pressure inside the pump body reaches a maximum point.
`
`In other words, although the safety
`
`relief valve which relieves a pressure is used in the conventional lubricating oil pump device
`
`only when the pressure thereinside reaches the maximum valve, the method in which the shaft of
`
`

`

`Attorney Docket No. PK3923598
`
`PCT/KR2018/015477
`
`the relief valve for protecting safety of the pump doubles as the shaft of the pressure detection
`
`sensor which controls the pressure used for each pipe length at the pressure at the maximum
`
`point has problemsin that it is impossible to estimate a particular pressure capable of damaging
`
`the device and to relieve an internal pressure or more which reachesthe particular pressure when
`
`the pressure detection sensor does not work.
`
`Also, due to the above problem, the pressure inside the lubricating oil pump deviceis not
`
`appropriately relieved such that the lubricating oil pump device in which a sealing function is
`
`very significant may be damaged.
`
`[Technical Solution]
`
`10
`
`One aspect of the present invention provides a lubricating oil pump device including a
`
`pump body (100) and a lubricating oil cartridge (200). Here, the pump body (100) includes a
`
`suction portion (111) which is connected to the lubricating oil cartridge (200) and receives a
`
`lubricating oil from the lubricating oil cartridge (200), a discharge portion (112) which is
`
`connected to a lubricating oil supply pipe (W) and supplies the lubricating oil to the lubricating
`
`15
`
`oil supply pipe (W), a piston (150) which reciprocates in the pump body (100) to supply the
`
`lubricating oil to the pump body (100) from the lubricating oil cartridge (200), a relief valve
`
`(160) for adjusting a pressure inside the pump body (100), a pressure sensor (170) for measuring
`
`the pressure inside the pump body (100), a control portion (300) which controls an operation of
`
`the piston (150) and an operation of the relief valve (160), a first pipe (110) formed between the
`
`20
`
`suction portion (111) and the discharge portion (112), a second pipe (120) formed between the
`
`first pipe (110) and the relief valve (160), a third pipe (130) formed between the first pipe (110)
`
`and the piston (150), and a fourth pipe (140) formed betweenthefirst pipe (110) and the pressure
`
`sensor (170). Here, the pressure sensor (170) senses a pressure inside the pump body (100)
`
`

`

`Attorney Docket No. PK3923598
`
`PCT/KR2018/015477
`
`through the fourth pipe (140). When the detected pressure exceeds a preset pressure,
`
`the
`
`control portion (106) controls an operation of the piston (150) to open the third pipe (130) using
`
`the pressurerelief signal.
`
`The relief valve (150) may include a spring and a valve shaft, and the valve shaft may
`
`includea lubricating oil transfer path for returning the lubricating oil.
`
`The fourth pipe (140) may be formed in an area adjacent to the discharge portion (112)
`
`and may be spaced apart from and parallel to a transfer pipe at which the relief valve (160) is
`
`formed.
`
`The fourth pipe (140) may be formed in an area adjacent to the discharge portion (112)
`
`10
`
`and may be spaced apart from and perpendicular to a transfer pipe at which therelief valve (160)
`
`is formed.
`
`Another aspect of the present invention provides a lubricating oil pump device including
`
`a pump body (100) and a lubricating oil cartridge (200). The pump body (100) includes a
`
`suction portion (111) which is connected to the lubricating oil cartridge (200) and receives a
`
`15
`
`lubricating oil from the lubricating oil cartridge (200), a discharge portion (112) which is
`
`connected to a lubricating oil supply pipe and supplies the lubricating oil to the lubricating oil
`
`supply pipe, a piston (150) which reciprocates in the pump body (100) to supply the lubricating
`
`oil to the pump body (100) from the lubricating oil cartridge (200), a relief valve (160) for
`
`adjusting a pressure inside the pump body (100), a pressure sensor (170) for measuring the
`
`20
`
`pressure inside the pump body (100), a control portion (300) which controls an operation of the
`
`piston (150), a first pipe (110) formed between the suction portion (111) and the discharge
`
`portion (112), a second pipe (120) formed between thefirst pipe (110) and therelief valve (150),
`
`a third pipe (130) formed between the first pipe (110) and the piston (150), and a fourth pipe
`
`

`

`Attorney Docket No. PK3923598
`
`PCT/KR2018/015477
`
`(140) formed between the third pipe (130) and the pressure sensor (140). Here, the pressure
`
`sensor (170) detects a pressure inside the pump body (100) through the fourth pipe (140) and is
`
`configured to transmit a detection signal to the control portion (300) when the detected pressure
`
`is greater than or equal to a preset pressure. Here,
`
`the control portion (300) receives the
`
`detection signal from the pressure sensor (105) and controls an operation of the piston (103) to
`
`open the third pipe (130).
`
`The pressure sensor (170) may include a shaft and a pressure sensor which move
`
`backward according to a pressure in order to detect a pressure generated by the discharge portion
`
`(112) adjacent to the fourth pipe (140) and may transmit a measured pressure value to the control
`
`10
`
`portion (300) to maintain uniform pressure of the discharge portion (112).
`
`The pressure detection shaft and sensor may be located on oneside surface of the pump
`
`body (100) or located in a rear bracket attachment space of the pump body (100).
`
`The lubricating oil pump device may further include a pressure detection valve (172)
`
`which measures a pressure transferred from the fourth pipe (140) through a spring adjusting
`
`15
`
`screw, which sets a particular pressure, and a mobile shaft. Here, the pressure detection valve
`
`(172) may transmit the measured pressure to the pressure sensor (170).
`
`A movement distance of the mobile shaft may be adjusted by adjusting the spring
`
`adjusting screw of the pressure detection valve (172), and settings of the particular pressure of
`
`the pressure detection valve (172) may be changed by adjusting the movement distance of the
`
`20
`
`mobile shaft.
`
`Details of other embodiments are included in a detailed description and drawings.
`
`[Advantageous Effects]
`
`

`

`Attorney Docket No. PK3923598
`
`PCT/KR2018/015477
`
`According to the exemplary embodiments of the present disclosure, at least the following
`
`effects are provided.
`
`In a lubricating oil pump device provided herein, a pressure at a pipe through which a
`
`lubricating oil moves may be precisely measured. When the measuredpressure is greater than
`
`or equal to a particular preset pressure, a detection signal is transmitted to a control portion such
`
`that the control portion controls an operation of a piston to relieve a pressure inside a pump body.
`
`The lubricating pump device may be prevented from being damaged by relieving a pressure
`
`greater than or equal to a maximum point inside the pump body of the lubricating oil pump
`
`device. Accordingly, according to the present invention, since the pressure greater than or
`
`10
`
`equal to the maximum point may be adjusted and safely relieved using a relief valve, and a
`
`lubricating oil supply pressure detection piston control portion is separately used so as to set a
`
`precise pressure within a pressure use range, it is possible to prevent a change in a discharge
`
`amountof the lubricating oil and to supply a certain amountof the lubricating oil at a lubricating
`
`oil distribution supply side.
`
`15
`
`Effects according to the present disclosure are not restricted by the above exemplified
`
`content, and a variety of effects are included in the specification.
`
`[Description of Drawings]
`
`FIG. 1 is a front view of a conventional lubricating oil pump device.
`
`FIG. 2 is a perspective view of a lubricating oil pump device according to the present
`
`20
`
`invention.
`
`FIG. 3 is a cross-sectional view of a lubricating oil pump device according to one
`
`embodimentof the present invention.
`
`

`

`Attorney Docket No. PK3923598
`
`PCT/KR2018/015477
`
`FIG. 4 is a cross-sectional view of a lubricating oil pump device according to another
`
`embodimentof the present invention.
`
`FIG. 5 is a flowchart illustrating controlling, by a control portion, of the lubricating oil
`
`pumpdevice according to the present invention.
`
`[Description of Reference Numerals]
`
`100: pump body
`
`110: first pipe
`
`111: suction portion
`
`112: discharge portion
`
`10
`
`120: second pipe
`
`130: third pipe
`
`140: fourth pipe
`
`150: piston
`
`155: actuator
`
`15
`
`160: relief valve
`
`170: pressure sensor
`
`172: pressure detection valve
`
`200: lubricating oil cartridge
`
`300: control portion
`
`20
`
`400: input/output terminal
`
`V: metering valve
`
`W: lubricating oil supply pipe
`
`[Modesof the Invention]
`
`

`

`Attorney Docket No. PK3923598
`
`PCT/KR2018/015477
`
`The terms or words used in the specification and the claims will not be interpreted while
`
`being defined as general or lexical meanings and should be interpreted as meanings and concepts
`
`corresponding to the technical concept of
`
`the present
`
`invention.
`
`Accordingly,
`
`since
`
`embodiments disclosed in the specification and components shownin the drawings are merely
`
`exemplary embodiments of the present invention and do not represent an entirety of the technical
`
`concept of the present invention, it should be understood that a variety of equivalents and
`
`modifications capable of substituting the embodiments and the components maybepresent at the
`
`timeoffiling of the presents application.
`
`FIG. 1 is a front view of a conventional lubricating oil pump device.
`
`10
`
`Referring to FIG. 1, conventional lubricating oil pump devices each include, as shown in
`
`FIG. 1, a tank 2 which accommodates a lubricating oil formed of grease, a tank mounting portion
`
`3 which is installed above a pump body 10 and on which the tank 2 is mounted, and a cover
`
`mounted on the tank mounting portion 3 to cover the tank 2. The tank 2 is an axially retractile
`
`resinous cartridge container, and a male screw 5a is formed at an opening portion 5. The tank
`
`15
`
`mounting portion 3 includes a female screw portion 6 with which the male screw 5a of the
`
`opening portion 5 of the tank 2 is coupled to be mounted thereon. Also, the tank mounting
`
`portion 3 includes a guide pipe 7 which is inserted into the opening portion 5 of the tank 2
`
`inserted into and mounted on the male screw portion 6 and leads the lubricating oil in the tank 2
`
`to an inlet 11 of the pump body 10.
`
`20
`
`The pump body 10 includes, as shown in FIG. 1, a suction path 12 which suctions in the
`
`lubricating oil stored in the tank 2 through the inlet 11 and a discharge path 14 which discharges
`
`the suctioned lubricating oil through an outlet 13. The inlet 11 is open above the pump body 10
`
`and is connected to the guide pipe7.
`
`10
`
`

`

`Attorney Docket No. PK3923598
`
`PCT/KR2018/015477
`
`Also, the outlet 13 is open below the pump body 10. Also, a lubricating oil pipe W is
`
`connected to the outlet 13.
`
`Also, the pump body 10 includes a base end portion 15a located at a first side surface 10a
`
`of the pump body 10 and a cylinder portion 15 having an axialline in a lateral direction. A fore
`
`end portion 15b of the cylinder portion 15 includes an introduction hole 16 which communicates
`
`with the suction path 12 and introduces the lubricating oil from the suction path 12, and an
`
`elicitation hole 17 which communicates with the discharge path 14 and elicits the lubricating oil
`
`toward the discharge path 14. Also, a body portion 15c which forms the cylinder portion 15 is
`
`formed as a cylindrical memberand engageswith a hole 18 formed in the pump body10.
`
`10
`
`An inlet check valve 19 which allows only suction is installed ahead of the introduction
`
`hole 16, and an outlet check valve 20 which allows only discharge is installed behind the
`
`elicitation hole 17.
`
`The outlet check valve 20 includes a valve body 21. The valve body 21 includes a
`
`metallic head 23 having a conic support shape formed at a fore end of a rod 22, a rubber O-ring
`
`15
`
`24 continuously installed at a base end of the head 23 and fitting on the rod 22, and a push
`
`member 25 which pushes the O-ring 24 toward the base end of the head 23. Also, the outlet
`
`check valve 20 includes a metallic sealing surface portion 26 which is installed next to the
`
`elicitation hole 17 of the cylinder portion 15 and comesinto contact with or is separated from the
`
`head 23 and O-ring 24 of the valve body 21, a guide portion 27 which supports the rod 22 of the
`
`20
`
`valve body 21 to be movable in an axial direction and includesa slit-shaped path 27a passing the
`
`lubricating oil discharged from the elicitation hole 17 when the head 23 and O-ring 24 are
`
`separated from the sealing surface portion 26, and a coil spring 28 which is mounted between the
`
`11
`
`

`

`Attorney Docket No. PK3923598
`
`PCT/KR2018/015477
`
`guide portion 27 and the push member25 andpresses the head 23 and the O-ring 24 against the
`
`sealing surface portion 26.
`
`According to the outlet check valve 20, since the metallic head 23 and the rubber O-ring
`
`24 comeinto contact with the sealing surface portion 26 such that the rubber O-ring 24 is joined
`
`to the metallic sealing surface portion 26 in addition to metallic joining between the head 23 and
`
`the sealing surface portion 26, sealing is ensured that much and a countercurrent is certainly
`
`suppressed when the lubricating oil is absorbed through the introduction hole 16 so as to easily
`
`perform an operation.
`
`In the cylinder portion 15, a piston 30 is inserted to be movable forward and backward.
`
`10
`
`The piston 30 suctions the lubricating oil from the introduction hole 16 while moving backward
`
`and discharges the lubricating oil from the elicitation hole 17 while moving forward. A rear
`
`side portion 31 of the piston 30 protrudes outward from the base end 15a of the cylinder portion
`
`15 (that is, the side surface 10a of the pump body 10) and is linked with an actuator 40 even
`
`whenthe piston 30 moves forward.
`
`15
`
`The actuator 40, as shown in FIG. 1, moves the piston 30 forward or backward,
`
`introduces the lubricating oil from the introduction hole 16 of the cylinder portion 15 while the
`
`piston 30 moves backward and elicits the lubricating oil from the elicitation hole 17 of the
`
`cylinder portion 15 while the piston moves forward.
`
`In more detail, the actuator 40 includes an
`
`electric motor 41 capable of rotating forward and backward.
`
`Theelectric motor 41 includes a
`
`20
`
`driving shaft 43 rotating through a gear speed-reduction tool 42 andis fixed to a leg portion 44
`
`erected on thefirst side surface 10a of the pump body 10 suchthat an axialline of the shaft 43 is
`
`parallel to an axial line of the piston 30. At the driving shaft 43 of the electric motor 41, a
`
`screw shaft 45 on the same axis extends. A fore end portion of the screw shaft 45 is rotatably
`
`12
`
`

`

`Attorney Docket No. PK3923598
`
`PCT/KR2018/015477
`
`supported at the first side surface 10a of the pump body 10 using a bearing 46. Also, the
`
`actuator 40 includes a link member 47 which engages with the screw shaft 45 andis fixed to and
`
`linked with the rear side portion 31 of the piston 30.
`
`The link member 47 is slidably supported at two guide shafts 48 and is moved forward
`
`and backward by forward and backward rotation of the screw shaft 45 so as to move the piston
`
`30 forward and backward. Due to forward and backward movement of the piston 30, a
`
`lubricating oil is supplied to a lubricant pipe W connected to the outlet 13 and the outlet 13 is
`
`pressurized whenthe lubricating oil is supplied.
`
`Also,
`
`the piston 30 is movable to move forward to a first position Pl which is an
`
`10
`
`advancing end of a fore end 32 of the piston 30 which moves forward andelicits the lubricating
`
`oil, to a second position P2 at which the piston 30 is moved backward from thefirst position P1
`
`and absorbs the lubricating oil, and to a third position P3 at which the piston 30 is moved
`
`backward from the second position P2._ Also, the pump body 10 includesa pressure relief path
`
`50 formed therein, which is closed by the piston 30 when the piston 30 moves between thefirst
`
`15
`
`position Pl and the second position P2 and is opened by the piston 30 whenthe piston 30 is
`
`moved backwardto the third position P3. Accordingly, when supplying of the lubricating oil
`
`through the lubricating oil pipe is stopped, the piston 30 may be moved backward to the third
`
`position P3 and a pressureat the outlet 13 may be removed.
`
`In more detail, as shownin FIG. 1, a first through hole 51 and a second through hole 52
`
`20
`
`are formed in the cylinder portion 15 of the pump body 10. The first through hole 51 and the
`
`second through hole 52 are closed by the piston 30 when the piston 30 moves between thefirst
`
`position P1 and the second position P2 and are opened whenthe piston 30 moves backward to
`
`the third position P3. Also, a first path 53, which connects the first through hole 51 to the
`
`13
`
`

`

`Attorney Docket No. PK3923598
`
`PCT/KR2018/015477
`
`discharge path 14, and a second path 54, which connects the second through hole 52 to the
`
`suction path 12, are formed in the pump body 10. Accordingly, the pressure relief path 50
`
`which passesthe discharge path 14, the first path 53, the cylinder portion 15, and the second path
`
`54 and reaches the suction path 12 when the piston 30 moves backwardto the third position P3
`
`may be formed.
`
`FIGS. 2 and 3 are front and side views of a lubricating oil pump device according to one
`
`embodimentof the present invention.
`
`The lubricating oil pump device, as shown in FIGS. 2 and 3, includes a pump body 100
`
`and a lubricating oil cartridge 200.
`
`Schematically, the lubricating oil pump device stores a
`
`10
`
`lubricating oil in the lubricating oil cartridge 200 and supplies and dischargesthe lubricating oil
`
`stored in the lubricating oil cartridge 200 through a lubricating oil pipe formed in the pump body
`
`100. Also, the lubricating oil pipe is connected to a discharge portion 112 of the lubricating oil
`
`pumpdevice, and the lubricating oil discharged from the discharge portion 112 is supplied into
`
`an injection molding device through the lubricating oil pipe and a metering valve V.
`
`15
`
`Additionally, the lubricating oil pump device includesa fixing clip for fixing the device to a wall
`
`or another device.
`
`A lubricating oil supply device according to one embodiment of the present invention
`
`includes the pump body 100 includingafirst pipe 110, a second pipe 120, third pipes 131 and
`
`132, and a fourth pipe 140, the lubricating oil cartridge 200 installed on the pump body 100 to be
`
`20
`
`connected to one end of the first pipe 110 and including a tank storing a lubricating oil and a
`
`housing covering the tank, a piston 150 moving forward and backward while repetitively
`
`opening and closing the third pipes 131 and 132 and transferring the lubricating oil through a
`
`lubricating oil transfer pipe 110, an actuator 155 moving the piston forward or backward,a relief
`
`14
`
`

`

`Attorney Docket No. PK3923598
`
`PCT/KR2018/015477
`
`valve 160 installed at a connecting part between the fourth pipe 140 and the other end of the
`
`second pipe 120, a pressure sensor 170 formed at one end of the fourth pipe 140 to measure a
`
`pressure of the lubricating oil in the pump body 100, and a control portion 300 controlling the
`
`actuator 155 and the relief valve 160 on the basis of information transmitted from the pressure
`
`sensor 170. Also, the pump body 100 may be connected to a plurality of such metering valves
`
`V through a lubricating oil pipe W.
`
`The pump body 100 includesa suction portion 111 for receiving the lubricating oil stored
`
`in the lubricating oil cartridge 200 and the discharge portion 112 for discharging the suctioned
`
`lubricating oil. The suction portion 111 is disposed above the pump body 100, the discharge
`
`10
`
`portion 112 is disposed below the pump body 100, and the first pipe 110 is formed between the
`
`suction portion 111 and the discharge portion 112 to transfer the lubricating oil while passing
`
`through the pump body. Also, at the suction portion 111 and the discharge portion 112, an
`
`incoming-side check valve is installed to prevent the lubricating oil moved to the first pipe 110
`
`from flowing backward to the lubricating oil cartridge 200, and an outgoing-side check valveis
`
`15
`
`installed to prevent the lubricating oil supplied to the lubricating oil supply pipe W from flowing
`
`backward to the first pipe 110.
`
`Thefirst pipe 110 is connected to the second pipe 120, the third
`
`pipe 130, and the fourth pipe 140. The second pipe 120 connects a transfer pipe of the relief
`
`valve 160 located at a branch ofthe first pipe 110 to the first pipe 110 with the relief valve 160
`
`therebetweenso as to allow the first pipe 110 and the second pipe 120 to communicate with each
`
`20
`
`other only when a shaft of the relief valve 160 is moved hindmost due to occurrence of a
`
`maximumpressure.
`
`The third pipe 130 mayincludeafirst pressure relief pipe 131 connected to one side of
`
`the first pipe 110 and a secondpressure relief pipe 132 connected to the other side of the first
`
`15
`
`

`

`Attorney Docket No. PK3923598
`
`PCT/KR2018/015477
`
`pipe 110. The first pressure relief pipe 131 and the second pressure relief pipe 132 may be
`
`connected to each other or not connected depending on a position of a shaft of the piston 150.
`
`In more detail, the piston 150 is movable to be located at a first position which is a maximum
`
`advancing point of the shaft of the piston 150 which moves forward andelicits the lubricating oil,
`
`a second position which is a maximum retreat point of an action of absorbing the lubricating oil
`
`while moving backward from the first position, and a third position which is a point where the
`
`shaft of the piston 150 moves back again from the second position and may open the first
`
`pressure relief pipe 131 and the second pressure relief pipe 132. Also, the pump body 100
`
`includes a third pipe 130 formed therein, which is closed by the piston 150 when the piston 150
`
`10
`
`moves between the first position and the second position and is opened by the piston 150 when
`
`the piston 150 is moved backward to the third position P3. Accordingly, when supplying of the
`
`lubricating oil
`
`through the lubricating oil pipe is stopped,
`
`the piston 150 may be moved
`
`backward to the third position and a pressure at the discharge portion 112 may berelieved.
`
`The fourth pipe 140 is one of branchesof the first pipe 110 and may be formed adjacent
`
`15
`
`to the discharge portion 112 in order to measure a pressure applied to the discharge portion 112.
`
`The fourth pipe may be formed to be spaced to be parallel to or perpendicular to a movement
`
`pipe at which the relief valve 160 is located. The fourth pipe 140 is a pipe formed to measure a
`
`level of the pressure applied to the pump, and a pressure sensor 170 may be formed at an end of
`
`the correspondingpipe.
`
`20
`
`The piston 150 is inserted into the pump body 100 and reciprocates forward and
`
`backward along an operation path formed in the pump body 100.
`
`Since the piston 150
`
`reciprocates forward and backward in the pump body 100, the lubricating oil is absorbed into the
`
`first pipe 110 of the pump body 100 through the suction portion 111 from the lubricating oil
`
`16
`
`

`

`Attorney Docket No. PK3923598
`
`PCT/KR2018/015477
`
`cartridge 200 and is discharged into the lubricating oil supply pipe W through the discharge
`
`portion 112.
`
`In more detail, when the piston 150 moves backward to the second position, the
`
`lubricating oil is absorbed into the first pipe from the lubricating oil cartridge. When the piston
`
`150 moves forward to the first position, the lubricating oil of the first pipe is discharged into the
`
`lubricating oil supply pipe W through the discharge portion 112. Reciprocation of the piston
`
`103 may be controlled by the control portion 300 and maybeinstalled to be located at three or
`
`more positions (for example, the first position, the second position, and the third position). As
`
`described above, when reciprocation is performed between the first position and the second
`
`position,
`
`the reciprocating oil is pumped and supplied to the lubricating oil supply pipe W
`
`10
`
`through the first pipe 110. When moving backwardto the third position, the pressure in the
`
`pump may be relieved by opening the third pipe. The piston 150 may be operated by the
`
`actuator 155.
`
`The actuator 155 may include an electric motor and the like capable of rotating forward
`
`or backward.
`
`Theelectric motor has a driving shaft rotated by a gear speed reduction tool and
`
`15
`
`is disposed such that a shaft line of a shaft is parallel to an axial line of the piston 150. A
`
`coaxial screw shaft 151 may be installed at and extend from the driving shaft of the electric
`
`motor. The actuator 155 may include a link member which is engaged with the screw shaft 151
`
`and is fixed and linkedto a rear side part of the piston 150.
`
`The link member maybe supported to be slidable by two guide shafts and may be moved
`
`20
`
`forward and backward by forward and backward rotation of the screw shaft 151 to move the
`
`piston 150 forward and backward.
`
`The relief valve 160 is inserted into the pump body 100 and is generally installe