Attachment for grease discharge device, grease discharge device, hose for grease discharge device, coupler unit for grease discharge device

Abstract

To effectively prevent breakage of a hose and a coupler unit connected to a discharge port.SOLUTION: In a grease gun which comprises: a pump; a discharge passage from which a grease is discharged by the operation of the pump; a relief valve provided at the discharge passage for releasing the pressure in the discharge passage; and a discharge port which is provided further on the downstream side than the relief valve and to which a hose 36 is connected, an attachment 40 for grease gun can be connected between the hose 36 and a coupler unit 80 connected to the hose 36. Then, the attachment 40 for grease gun includes: a pressure relief valve 43 for releasing the pressure of the grease when the pressure of the grease passing inside surpasses a predetermined working pressure lower than a pressure at which the relief valve operates; and an adjustment knob 44 capable of adjusting the working pressure.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to an attachment for a grease discharging device used in a grease discharging device such as a grease gun, a grease discharging device, a hose for a grease discharging device, and a coupler unit for a grease discharging device. [Background technology]

[0002] As a grease discharge device, for example, Patent Document 1 discloses a grease gun having a tank for storing grease, a housing connected to the tank, a motor contained in the housing, and a pump driven by the motor. In this grease gun, when the plunger of the pump reciprocates as the motor is driven, the grease in the tank is pressure-fed and discharged from a discharge port. The pump is also provided with a relief valve that operates when the pressure in the discharge passage reaches or exceeds a predetermined value to release the grease to the outside. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-102989 Summary of the Invention [Problem to be solved by the invention]

[0004] Work with a grease gun is performed by connecting a hose to the discharge port, or connecting a coupler unit (a coupler that can be connected to a grease inlet of an external device, attached to the end of a pipe, sometimes called an "adapter") to the end of the hose, and discharging grease to the required location from the end of the hose or coupler unit held by the worker.In this case, if the pressure compensation of the hose or coupler unit is lower than the operating pressure of the relief valve, there is a risk that the hose or coupler unit will be damaged by the pressure before the relief valve operates.

[0005] Therefore, the present disclosure aims to provide an attachment for a grease discharge device, a grease discharge device, a hose for a grease discharge device, and a coupler unit for a grease discharge device that can effectively prevent damage to the hose and coupler unit connected to the discharge port. [Means for solving the problem]

[0006] In order to achieve the above object, a first configuration of the present disclosure is an attachment for a grease discharging device, which includes a pump, a discharge path for grease discharged by operation of the pump, a relief valve provided in the discharge path for relieving pressure within the discharge path, and a discharge port provided downstream of the relief valve and to which is connected a coupler unit formed by connecting a coupler to the end of a hose or pipe, and which may be connectable between the discharge port and the hose or the coupler unit, or between the hose and the coupler unit connected to the hose. The attachment for the grease discharge device may be equipped with a pressure relief valve that releases the pressure of the grease when the pressure of the grease passing through it exceeds a predetermined operating pressure that is lower than the pressure at which the relief valve operates. The attachment for the grease discharge device may include an adjustment mechanism capable of adjusting the operating pressure. In order to achieve the above object, a second configuration of the present disclosure may be a grease discharge device including a pump, a discharge passage for grease discharged by operation of the pump, a relief valve provided in the discharge passage for releasing pressure within the discharge passage, and a discharge port provided downstream of the relief valve and connected to a coupler unit formed by connecting a coupler to the end of a hose or pipe. The grease discharge device may be configured by connecting an attachment for a grease discharge device according to any one of the first configurations between the discharge port and a hose or a coupler unit, or between a hose and a coupler unit connected to the hose. In order to achieve the above object, a third configuration of the present disclosure may be a hose for a grease discharging device, which is connected to a discharge port of a grease discharging device including a pump, a discharge passage for grease discharged by operation of the pump, a relief valve provided in the discharge passage for relieving pressure in the discharge passage, and a discharge port provided downstream of the relief valve. The hose for a grease discharge device may include a pressure relief valve that releases the pressure of the grease when the pressure of the grease discharged from the discharge port and passing through the inside exceeds a predetermined operating pressure lower than the pressure at which the relief valve operates, and an adjustment mechanism capable of adjusting the operating pressure. In order to achieve the above object, a fourth configuration of the present disclosure may be a coupler unit for a grease discharge device, which is connected to the discharge outlet of a grease discharge device including a pump, a discharge passage for grease discharged by operation of the pump, a relief valve provided in the discharge passage for releasing pressure in the discharge passage, and a discharge outlet provided downstream of the relief valve, and which has a coupler connected to the end of a pipe. The coupler unit for the grease discharge device may include a pressure relief valve that releases the pressure of the grease when the pressure of the grease discharged from the discharge port and passing through the interior exceeds a predetermined operating pressure that is lower than the pressure at which the relief valve operates, and an adjustment mechanism that can adjust the operating pressure. In order to achieve the above object, a fifth configuration of the present disclosure is an attachment for a grease discharge device, comprising a motor, a pump operated by driving the motor, a discharge path for grease discharged by operation of the pump, and a discharge port provided downstream of the discharge path and connected to a coupler unit formed by connecting a coupler to the end of a hose or pipe, and which may be connectable between the discharge port and the hose or the coupler unit, or between the hose and the coupler unit connected to the hose, in the grease discharge device which stops rotation of the motor when the current value of the motor reaches a predetermined value corresponding to a predetermined discharge pressure of the grease from the discharge port. The attachment for the grease discharge device may include a pressure relief valve that releases the pressure of the grease when the pressure of the grease passing through it exceeds a predetermined operating pressure that is lower than the predetermined discharge pressure, and an adjustment mechanism that can adjust the operating pressure. In order to achieve the above object, a sixth configuration of the present disclosure may be a grease discharge device including a motor, a pump operated by driving the motor, a discharge path for grease discharged by operation of the pump, a discharge port provided downstream of the discharge path, and a coupler connected to the discharge port to discharge the grease. The grease discharge device may include a first discharge pressure responding portion that releases the grease to the outside or stops the rotation of the motor when the discharge pressure of the grease in the discharge passage is a predetermined first pressure. The grease discharge device may include a second discharge pressure corresponding part that is provided between the discharge port and the coupler and that, when the discharge pressure of the grease at the discharge port is a predetermined second pressure lower than the first pressure, releases the grease to the outside without supplying it to the coupler. Effect of the Invention

[0007] According to the present disclosure, when the internal pressure of the hose or coupler unit increases, the pressure can be released before the relief valve of the grease discharge device operates or the motor stops rotating, thereby effectively preventing damage to the hose or coupler unit connected to the discharge port. [Brief description of the drawings]

[0008] [Figure 1] FIG. [Diagram 2] FIG. 2 is a central vertical cross-sectional view of the grease gun. [Diagram 3] FIG. 3 is a partial cross-sectional view taken along the line AA in FIG. [Figure 4] FIG. 4 is an enlarged cross-sectional view of a grease gun attachment portion. [Diagram 5] FIG. 2 is an exploded perspective view of the grease gun attachment. [Figure 6]13 is a perspective view of a grease gun equipped with a modified grease gun attachment. FIG. [Figure 7] FIG. 11 is an enlarged cross-sectional view of a grease gun attachment portion of a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] In one embodiment of the present disclosure, the grease discharge device attachment desirably includes a storage chamber capable of storing a predetermined amount of grease released by the pressure relief valve. According to this configuration, the grease released by the attachment for the grease discharge device can be temporarily stored, and the scattering of grease from the activated attachment for the grease discharge device can be suppressed. In one embodiment of the present disclosure, it is desirable for the storage chamber to be provided with a discharge portion that discharges grease that exceeds a predetermined amount to the outside. With this configuration, it is easier for an operator to notice that the pressure relief valve of the grease discharge device attachment has been activated. In one embodiment of the present disclosure, the reservoir is desirably formed in a ring shape centered around the pressure relief valve. According to this configuration, a large volume of the storage chamber can be ensured, and the released grease can be sufficiently stored.

[0010] In one embodiment of the present disclosure, it is desirable that the attachment for the grease discharge device includes a through hole to which the discharge port, the hose, and the coupler unit can be respectively connected, and a communication hole that connects the through hole with the storage chamber, and that the pressure relief valve includes a valve body provided in the communication hole that can open and close the outlet of the grease from the through hole, and an elastic member that biases the valve body toward the blocking side of the outlet. According to this configuration, the attachment for the grease discharge device can be formed compactly. In one embodiment of the present disclosure, the adjustment mechanism is desirably an adjustment knob capable of adjusting the biasing force on the valve body by pressing an elastic member with a screw feed operation. With this configuration, the operating pressure of the attachment for the grease discharge device can be easily adjusted. EXAMPLES

[0011] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. Fig. 1 is a perspective view of a grease gun attachment (hereinafter simply referred to as "attachment") 40 according to the first configuration. Fig. 1 is also a perspective view of a rechargeable grease gun 1, which is an example of a grease discharge device according to the second configuration. Here, a hose 36 is connected to discharge port 35 at the tip of grease gun 1 via joint 75A, and a coupler unit 80 is connected to the tip of hose 36 via attachment 40. Fig. 2 is a central vertical cross-sectional view of grease gun 1 and part of hose 36. First, the grease gun 1 will be described. The grease gun 1 has a main body housing 2. A cylindrical motor housing section 3 is formed at the bottom of the main body housing 2 so as to extend in the front-rear direction. A grip section 4 is formed at the top of the main body housing 2 so as to extend in the front-rear direction. The grip section 4 is connected to the motor housing section 3 in a loop shape. A battery attachment section 5 is provided at the rear end of the motor housing section 3. A controller 6 is housed in the battery attachment section 5. A battery pack 7 can be slidably attached from above to the battery attachment section 5.

[0012] A switch 8 is housed within the grip portion 4. The switch 8 has a trigger 9 that protrudes downward. A light 10 is provided on the front surface of the grip portion 4. A light switch 11 for turning the light 10 on and off is provided on the front upper surface of the grip portion 4. A lock-on button 12 that can maintain the pressed state of the trigger 9 is provided on the grip portion 4 in front of the trigger 9. A lock-off button 13 that restricts the pressing of the trigger 9 is provided below the lock-on button 12 and in front of the trigger 9. A motor 14 is accommodated within the motor housing section 3 with its output shaft 15 facing forward. A gear housing 16 is attached in front of the motor 14. A reduction gear mechanism 17 is accommodated in the gear housing 16. The reduction gear mechanism 17 reduces the rotation of the output shaft 15 and outputs the reduced rotation to a spindle 18. A crank mechanism 19 is provided in front of the spindle 18. The crank mechanism 19 converts the rotation of the spindle 18 into up and down movement of a slider 20. A downward-facing plunger 21 is integrally provided with the slider 20.

[0013] A cylindrical front holder 22 that opens to the rear is formed at the bottom of the gear housing 16. A tank 23 is connected to the front holder 22 from the rear. A rear holder 24 that protrudes downward is provided at the bottom of the motor housing portion 3 and behind the front holder 22. The rear holder 24 supports the tank 23 in the front-rear direction. A pump 25 is provided in the front holder 22. The pump 25 discharges grease supplied from the tank 23 by the up and down movement of the plunger 21. The pump 25 includes an upper cylinder portion 26 and a lower cylinder portion 27. The upper cylinder portion 26 protrudes downward from the upper inner surface of the front holder 22. The lower cylinder portion 27 protrudes upward from the lower inner surface of the front holder 22 coaxially with the upper cylinder portion 26. A gap 28 communicating with the inside of the front holder 22 is formed between the upper cylinder portion 26 and the lower cylinder portion 27. The plunger 21 moves up and down through the upper cylinder portion 26 and the lower cylinder portion 27. At the top dead center of the plunger 21, the lower end enters the upper cylinder portion 26 above the gap 28. At the bottom dead center of the plunger 21, the lower end reaches approximately the middle part of the lower cylinder portion 27. A vertical discharge passage 29 is formed in the lower cylinder portion 27. The vertical discharge passage 29 communicates with the gap 28 and the plunger 21 passes through it.

[0014] A lateral discharge passage 30 that communicates with the vertical discharge passage 29 is formed facing forward in the lower cylinder portion 27. The vertical discharge passage 29 and the lateral discharge passage 30 form a discharge passage for grease. A check valve 31 is provided at the lower end of the vertical discharge passage 29. The check valve 31 is provided to prevent the backflow of grease in the vertical discharge passage 29. 3, a connection passage 30a that opens into the right side surface of the front holder 22 is formed in communication with the lateral discharge passage 30. A relief valve 32 is provided in the connection passage 30a. The relief valve 32 includes a valve bolt 33 and a valve cover 34. The valve bolt 33 is screwed into the connection passage 30a. The valve cover 34 is attached to the head of the valve bolt 33 that protrudes from the right side surface of the front holder 22.

[0015] The valve bolt 33 has a relief passage 33a, a valve pin 33b, a ball 33c, a coil spring 33d, and a set screw 33e. The relief passage 33a extends in the axial direction in communication with the connection passage 30a, and then opens in the radial direction at the head of the valve bolt 33 as shown by the dotted line. The valve pin 33b holds a ball 33c at its tip and is movable in the axial direction. The coil spring 33d biases the valve pin 33b to the valve closing position in FIG. 3 where the ball 33c closes the relief passage 33a. The set screw 33e is screwed into the head of the valve bolt 33 and receives the end of the coil spring 33d. The valve pin 33b has a plurality of grooves 33f that communicate the relief passage 33a in the axial direction. In this relief valve 32, when the pressure of the grease in the lateral discharge passage 30 increases, the grease that has flowed into the connecting passage 30a presses the ball 33c against the bias of the coil spring 33d, moving the valve pin 33b to the valve open position that opens the relief passage 33a. Then, the grease in the relief passage 33a flows out from the head of the valve pin 33b through the groove 33f to the outside, allowing the pressure to be released.

[0016] A discharge port 35 in which the lateral discharge passage 30 is formed protrudes forward from the front surface of the front holder 22. A joint 75A provided at the rear end of a hose 36 is screwed and connected to the discharge port 35. Protective spiral covers 36a, 36a are fitted to both the front and rear ends of the hose 36. The tank 23 passes through the rear holder 24 from the rear, and its front end is connected to the front holder 22. A rod 37 having a piston 38 at its front end is provided in the tank 23 so as to be movable in the front-rear direction. A coil spring 39 is provided in the tank 23 to urge the piston 38 forward. If a cartridge (not shown) filled with grease is placed inside the tank 23, the grease is pushed out of the cartridge by the piston 38 which moves forward due to the force of the coil spring 39, and is then supplied to the pump 25.

[0017] As shown in FIGS. 4 and 5, the attachment 40 has a connecting portion 41, a grease reservoir 42, a pressure relief valve 43, and an adjustment knob 44. The connecting part 41 is a cylindrical block shape extending in the front-rear and left-right directions, and has a through hole 45 formed inside in the longitudinal direction. Female threads 46, 46 are formed at both the front and rear ends of the through hole 45. A receiving part 47 that is circular in plan view is formed on the upper surface of the connecting part 41. In this way, the lower part of the connecting part 41 excluding the receiving part 47 has a two-face width, which eliminates so-called excess material, leading to weight reduction and cost reduction. The grease reservoir 42 includes a lower disk 50, a middle tube 51, an upper disk 52, a communication hole 53, an outer tube 54, and an O-ring 55. The lower disk 50 is a disk-shaped disk in a plan view, and is coaxially and integrally formed on the upper surface of the receiving portion 47. A groove 56 is formed on the outer circumferential surface of the lower disk 50 over the entire circumference. The O-ring 55 is fitted to the lower disk 50 and engages with the groove 56. The middle tube 51 is a cylinder extending upward from the center of the upper surface of the lower disk 50. The upper disk 52 is a disk-shaped disk in a plan view that has the same diameter as the lower disk 50, and is coaxially and integrally formed on the upper end of the middle tube 51.

[0018] The communication hole 53 is formed coaxially in the middle cylinder portion 51 and is formed across the connecting portion 41, the lower disk portion 50, and the upper disk portion 52. The communication hole 53 has a small diameter hole portion 57, a medium diameter hole portion 58, a large diameter hole portion 59, and a through hole portion 60. The small diameter hole portion 57 is a hole with a circular cross section, and extends upward in communication with the center of the through hole 45 in the longitudinal direction in the connecting portion 41. The medium diameter hole portion 58 is a circular hole with a cross section larger than the small diameter hole portion 57, is connected coaxially with the small diameter hole portion 57 in the connecting portion 41, and extends upward through the lower disk portion 50 and the middle cylinder portion 51. The large diameter hole portion 59 is a circular hole with a cross section larger than the medium diameter hole portion 58, is connected coaxially with the medium diameter hole portion 58 in the middle cylinder portion 51, and opens to the upper surface by penetrating the upper disk portion 52. A female screw portion 61 is formed on the inner surface of the large diameter hole portion 59. The through hole portion 60 penetrates the center cylinder portion 51 in the diameter direction and communicates with the medium diameter hole portion 58. The outer cylinder 54 is fitted to the lower disk portion 50 and the upper disk portion 52, and placed on the receiving portion 47 of the connecting portion 41. An O-ring 55 is pressed against the inner circumference of the lower part of the lower disk portion 50 to seal the gap between the lower disk portion 50 and the outer cylinder 54 over the entire circumference. The outer cylinder 54 and the upper disk portion 52 are not in contact with each other, and a ring-shaped discharge port 62 is formed between them over the entire circumference. Therefore, a grease storage chamber 63 is formed in a ring shape inside the outer cylinder 54, surrounded by the lower disk portion 50, the middle cylinder portion 51, the upper disk portion 52, and the outer cylinder 54, and communicating with the through-hole portion 60 and the discharge port 62.

[0019] The pressure relief valve 43 is accommodated in the medium diameter hole portion 58 of the communication hole 53. The pressure relief valve 43 includes a valve body 65 and a coil spring 66. The valve body 65 is a shaft extending in the vertical direction, with a large-diameter head 67 formed integrally at its lower end. A circular recess 68 that opens downward is formed in the center of the underside of the head 67. A ball 69 fits into the circular recess 68, causing its lower portion to protrude from the underside of the head 67. An outlet 70 of the small-diameter hole portion 57 opens at the bottom surface of the medium-diameter hole portion 58. The ball 69 protruding from the underside of the head 67 is capable of closing the outlet 70. The coil spring 66 is fitted around the valve body 65 within the medium diameter hole portion 58 , and the lower end of the coil spring 66 is in contact with the upper surface of the head portion 67 .

[0020] The adjustment knob 44 has a threaded portion 71 at the center of the bottom surface. The threaded portion 71 protrudes downward and screws into the female threaded portion 61 of the large diameter hole portion 59. The upper end of the coil spring 66 abuts against the bottom surface of the threaded portion 71. Therefore, valve body 65 is urged downward by coil spring 66 to press ball 69 against outlet 70 of small diameter hole portion 57. This pressing force can be adjusted by rotating adjustment knob 44 to change the amount of screwing of threaded portion 71 and thereby change the axial length of coil spring 66. As a result, the operating pressure at which valve body 65 moves upward against the urging of coil spring 66 to open outlet 70 of small diameter hole portion 57 can be adjusted within a range of, for example, 15 to 20 MPa. This operating pressure is lower than the operating pressure (for example, 80 MPa) of relief valve 32 provided in grease gun 1.

[0021] The coupler unit 80 includes a pipe 81 and a coupler 82 connected to the front end of the pipe 81. The pipe 81 includes threaded portions 83, 83 on both the front and rear ends. The coupler 82 includes a head 84, a cap 85, a ball 86, a coil spring 87, a seal sleeve 88, a rigid sleeve 89, and a chuck jaw 90. The seal sleeve 88 is made of rubber, and the others are made of metal such as iron. The head 84 is sleeve-shaped and is connected to the pipe 81 by screwing in the threaded portion 83 at the front end of the pipe 81. The cap 85 is sleeve-shaped and is connected to the head 84 by screwing in the threaded portion at the front end of the head 84. The ball 86 is movably held in the front end of the head 84 and can open and close a valve seat 91 in the head 84. A coil spring 87, a seal sleeve 88, a rigid sleeve 89, and a chuck claw 90 are housed in the cap 85 in front of the head 84 in this order. A stopper 92 that prevents the chuck claw 90 from coming off is provided on the inner periphery of the front end of the cap 85. The coil spring 87 is disposed between the ball 86 and the seal sleeve 88 to bias the ball 86 to a valve-closing position, and forms a check valve together with the ball 86. The rigid sleeve 89 abuts against the chuck claw 90 to position the seal sleeve 88. The chuck jaws 90 are housed at the front end of the cap 85 so as to be elastically expandable and are normally biased to contract.

[0022] Therefore, in the coupler 82, the valve seat 91 is closed by the ball 86 biased by the coil spring 87 in the normal state. When supplying grease, a nipple 93, which is a grease inlet provided on an external device such as an agricultural machine, is inserted into the tip of the cap 85. Then, as shown by the two-dot chain line in FIG. 4, the ball-shaped tip 94 of the nipple 93 pushes the chuck jaws 90 apart and enters the chuck jaws 90, and abuts against the front end surface of the seal sleeve 88. When the chuck jaws 90 relatively overcome the tip 94 of the nipple 93, they contract and elastically grip the tip 94. Thus, the nipple 93 is connected to the coupler 82, and an internal flow path with a check valve communicates with the inside of the seal sleeve 88.

[0023] The attachment 40 configured as described above is connected by screwing the joint 75B provided at the front end of the hose 36 into one of the female threaded portions 46 of the through hole 45 of the connecting portion 41. Also, the threaded portion 83 of the pipe 81 of the coupler unit 80 is screwed into the other female threaded portion 46 of the through hole 45. Then, the connecting portion 41 is connected between the hose 36 and the coupler unit 80, and the through hole 45 is in communication with the hose 36 and the inside of the coupler unit 80. In the grease gun 1, the trigger 9 is pressed while the tank 23 containing the cartridge is connected to the front holder 22. Then, the controller 6 detects the signal from the switch 8 and supplies a drive current to the motor 14 to rotate the output shaft 15. The rotation of the output shaft 15 is decelerated by the reduction mechanism 17 and transmitted to the spindle 18. In the crank mechanism 19, the rotation of the spindle 18 is converted into the vertical movement of the slider 20, and the plunger 21 reciprocates up and down. Therefore, in the pump 25, when the plunger 21 reaches the top dead center, the grease flows from the gap 28 between the upper cylinder portion 26 and the lower cylinder portion 27 into the vertical discharge passage 29 of the lower cylinder portion 27. When the plunger 21 then moves to the bottom dead center, the grease pushed downward in the vertical discharge passage 29 flows into the horizontal discharge passage 30 and is discharged directly through the discharge port 35 into the hose 36. This discharge operation is repeated with the reciprocating movement of the plunger 21.

[0024] The grease that has passed through the hose 36 passes through the through hole 45 in the connecting portion 41 of the attachment 40, and then flows into the pipe 81 of the coupler unit 80. The grease supplied from the pipe 81 to the coupler 82 presses the ball 86 as it passes through the head 84, moving it away from the valve seat 91, and flows into the seal sleeve 88. When the coupler 82 is connected to the nipple 93 as described above, the grease is supplied to an external device via the nipple 93.

[0025] In the attachment 40, when the pressure of the grease in the through hole 45 exceeds the operating pressure set by the adjustment knob 44, the valve body 65 of the pressure relief valve 43 moves upward as described above to open the outlet 70 of the small diameter hole portion 57. Then, the grease in the through hole 45 flows from the small diameter hole portion 57 into the medium diameter hole portion 58 and flows into the storage chamber 63 through the through hole portion 60. By releasing the pressure in the through hole 45 in this way, an excessive pressure rise in the hose 36 and the coupler unit 80 is prevented. Therefore, the risk of damage to the hose 36 and the coupler unit 80 is reduced. In addition, by storing the grease in the storage chamber 63, the relieved grease does not immediately scatter to the outside. When the storage chamber 63 is filled with grease, the grease leaks out through the outlet 62 between the upper disk portion 52 and the outer cylinder 54. Therefore, an operator holding the coupler unit 80 can easily notice that the pressure relief valve 43 of the attachment 40 has been activated. After the work using the grease gun 1 is completed, the adjustment knob 44 of the attachment 40 is loosened to reduce the pressing force on the coil spring 66, and the pressure from the grease filled in the hose 36 and the coupler unit 80 is released from the communication hole 53 to the storage chamber 63. This makes it easier to remove the coupler unit 80 from the nipple 93.

[0026] In this way, the attachment 40 of the above embodiment can be connected between the hose 36 connected to the discharge port 35 and the coupler unit 80 connected to the hose 36 in a grease gun 1 which includes a pump 25, a vertical discharge passage 29 and a horizontal discharge passage 30 (an example of a discharge passage) through which grease is discharged by operation of the pump 25, a relief valve 32 provided in the horizontal discharge passage 30 for releasing pressure in the discharge passage, and a discharge port 35 provided downstream of the relief valve 32 and to which a hose 36 is connected. The attachment 40 includes a pressure relief valve 43 that releases the pressure of the grease passing through it when the pressure of the grease passing through it exceeds a predetermined operating pressure that is lower than the pressure at which the relief valve 32 operates, and an adjustment knob 44 (an example of an adjustment mechanism) that can adjust the operating pressure. According to this configuration, even if the pressure compensation of the hose 36 or the coupler unit 80 is lower than the operating pressure of the relief valve 32, when the internal pressure of the hose 36 or the coupler unit 80 increases, the pressure can be released before the relief valve 32 operates. Therefore, damage to the hose 36 or the coupler unit 80 connected to the discharge port 35 can be effectively prevented.

[0027] The attachment 40 is provided with a storage chamber 63 capable of storing a predetermined amount of grease released by the pressure relief valve 43. Therefore, the grease released by the attachment 40 can be temporarily stored, and the scattering of grease from the activated attachment 40 can be suppressed. The storage chamber 63 is provided with a discharge port 62 (an example of a discharge portion) for discharging grease that exceeds a predetermined amount to the outside. This makes it easier for the operator to notice that the pressure relief valve 43 of the attachment 40 has been activated. The storage chamber 63 is formed in a ring shape with the pressure relief valve 43 at its center. Therefore, a large volume of the storage chamber 63 can be ensured, and the released grease can be sufficiently stored.

[0028] The attachment 40 includes a through hole 45 to which the hose 36 and the coupler unit 80 can be connected, and a communication hole 53 that communicates the through hole 45 with the storage chamber 63. The pressure relief valve 43 includes a valve body 65 that is provided in the communication hole 53 and can open and close an outlet 70 for grease from the through hole 45, and a coil spring 66 (an example of an elastic member) that biases the valve body 65 toward the closing side of the outlet 70. Therefore, the attachment 40 can be formed compactly. The adjustment mechanism is an adjustment knob 44 that can adjust the biasing force on the valve body 65 by pressing a coil spring 66 with a screw feed operation. Therefore, the operating pressure of the attachment 40 can be easily adjusted.

[0029] Modifications of the present disclosure will be described below. In the above embodiment, the attachment is connected between the hose and the coupler unit, but the attachment may be connected between the outlet and the hose or coupler unit connected to the outlet. Figures 6 and 7 show an example in which the attachment 40 is connected between the outlet 35 and the hose 36. Here, a second cylinder 102 (described later) of a connector 100 which is screwed and connected to the tip of the discharge port 35 is screwed and connected to one of the female threads 46 of the through hole 45 of the connecting part 41. A joint 75A provided at the rear end of the hose 36 is screwed and connected to the other female thread 46. A coupler 82 is connected to the front end of the hose 36.

[0030] The connector 100 has a first cylinder 101, a second cylinder 102, and a cylinder joint 103. The first cylinder 101 is sleeve-shaped, and a flange 104 is formed in the middle. An O-ring 105 is attached to the rear side of the flange 104. A threaded portion 106 is formed in the front end of the first cylinder 101. A threaded portion 107 is formed in the rear end of the first cylinder 101. The second cylinder 102 is sleeve-shaped, and its rear end is coaxially inserted into the front end of the first cylinder 101. A flange 108 that abuts against the front end of the first cylinder 101 is formed at the rear of the second cylinder 102. An O-ring 109 is fitted to the exterior of the rear end of the second cylinder 102. A threaded portion 110 is formed at the front end of the second cylinder 102. The cylinder joint 103 is in the shape of a sleeve through which the second cylinder 102 can pass, and a locking portion 111 that locks onto the flange 108 of the second cylinder 102 is formed on the inner periphery of the front end. The threaded portion 106 of the first cylinder 101 can be screwed onto the inner periphery of the rear part of the cylinder joint 103.

[0031] In the connector 100, a threaded portion 107 at the rear end of the first cylinder 101 is screwed and coupled to the discharge port 35. A cylinder joint 103, through which the second cylinder 102 passes, is screwed and coupled to a threaded portion 106 at the front end of the first cylinder 101. Thus, the connector 100 is coaxially coupled to the discharge port 35. In this state, the O-ring 105 seals between the discharge port 35 and the first cylinder 101. The O-ring 109 seals between the first cylinder 101 and the second cylinder 102. A threaded portion 110 of the second cylinder 102 is screwed and coupled to the female threaded portion 46 of the through hole 45 of the coupling portion 41, thereby coupling to the attachment 40. Here, since the diameters of the threaded portion 110 of the second cylinder and the joint 75A are different, the connecting portion 41 has a greater vertical thickness than in the previous embodiment, but the other configurations and operations of the attachment 40 are the same as those in the above embodiment. However, the form of the connector is not limited to the above example, and one of the first and second cylinders may be omitted to connect the discharge port and the connecting part with only one cylinder. Depending on the shapes of the discharge port and the connecting part, the connecting part may be connected directly to the discharge port without using a connector.

[0032] The attachment is not limited to the above-mentioned examples in which the attachment is provided separately from the hose and the cap unit and screwed together. For example, the attachment may be provided integrally with the hose to form a hose with an attachment (the hose for a grease discharge device according to the third configuration). In this case, the attachment may be located at the front end of the hose or at the middle of the hose. The attachment and the hose can be integrated by fixing the connecting part to the hose with screws or by forming the connecting part integrally with the hose. Similarly, the attachment can be provided integrally with the grease discharge unit to form a grease discharge unit with an attachment (the grease discharge unit for the fourth configuration). In this case, the attachment can be located between the pipe and the grease discharge unit, or at the rear end or middle of the pipe. The attachment and coupler unit can be integrated by fixing the connecting part to the pipe or coupler with screws or by forming the connecting part integrally with the pipe or coupler.

[0033] The structure of the attachment itself is not limited to that of the above embodiment. The reservoir chamber of the grease reservoir does not have to be ring-shaped. The volume of the reservoir chamber can be increased or decreased as appropriate. The discharge part for the grease from the storage chamber is not limited to the discharge port in the above embodiment. For example, the upper disk part and the outer cylinder may be sealed with an O-ring or the like, and one or more through holes communicating with the storage chamber may be formed in the upper disk part or the outer cylinder to serve as the discharge part. The discharge part may be provided on the lower surface of the attachment. However, it is possible to omit the storage chamber and configure the released grease to be immediately discharged to the outside. The pressure relief valve may have a hemispherical protrusion integrally formed on the lower surface of the valve body instead of a ball on the valve body. The number of coil springs is not limited to one, and multiple coil springs (for example, double coil springs) may be provided. The elastic member is not limited to a coil spring, but a disc spring or the like can also be used. The communication holes and the pressure relief valve may be provided sideways instead of vertically. The adjustment mechanism can also be changed as appropriate depending on the position and structure of the pressure relief valve. For example, if the pressure relief valve is oriented horizontally, the adjustment knob can also be oriented horizontally. The adjustment mechanism is not limited to an adjustment knob. For example, the adjustment mechanism can be a set screw with a hexagonal hole that can be rotated. The operating pressure that can be adjusted by the adjustment mechanism is not limited to the above embodiment and can be changed as appropriate. The connection between the attachment and the hose and the cabriole unit is not limited to a screw-in connection, but a plug-in structure or the like can also be used.

[0034] The grease discharge device is not limited to the grease gun of the above embodiment. For example, the motor may be a brushless motor. The grease discharge device may be configured such that the tank is supported vertically instead of longitudinally, and the motor housing and the grip are formed vertically. The battery pack may be multiple, and the grease discharging device may be an AC machine that does not use a battery pack. The grease discharge device is not limited to one that releases pressure in the discharge passage by a relief valve. For example, instead of the relief valve, a controller may monitor the current flowing through the motor, and when the pressure in the discharge passage reaches a predetermined current value corresponding to the discharge pressure at which the relief valve operates, the controller may control the motor to stop rotating. In this grease discharge device, an attachment connected between the discharge port and the hose or connector, or between the hose and the coupler unit connected to the hose corresponds to the fifth configuration of the present disclosure.

[0035] In addition, the following disclosure as a grease discharge device can be extracted from the above embodiment. This corresponds to the sixth configuration of the present disclosure. A grease discharge device including a motor, a pump operated by driving the motor, a discharge path for grease discharged by operation of the pump, a discharge port provided downstream of the discharge path, and a coupler connected to the discharge port to discharge the grease, a first discharge pressure responding unit (e.g., a relief valve 32 or a controller 6) that releases the grease to the outside or stops the rotation of the motor when the discharge pressure of the grease in the discharge passage is a predetermined first pressure (e.g., 80 MPa); and a second discharge pressure corresponding part (e.g., attachment 40) that is provided between the discharge port and the coupler and that releases the grease to the outside without supplying it to the coupler when the discharge pressure of the grease at the discharge port is a predetermined second pressure (e.g., 15 to 20 MPa) that is lower than the first pressure. [Explanation of symbols]

[0036] DESCRIPTION OF SYMBOLS 1··Grease gun, 2··Main housing, 3··Motor housing section, 4··Grip section, 6··Controller, 14··Motor, 15··Output shaft, 17··Reduction mechanism, 19··Crank mechanism, 21··Plunger, 22··Front holder, 23··Tank, 25··Pump, 29··Vertical discharge passage, 30··Horizontal discharge passage, 32··Relief valve, 35··Discharge port, 36··Hose, 40··Grease gun attachment, 41··Connecting section, 42··Grease reservoir part, 43··pressure relief valve, 44··adjustment knob, 45··through hole, 46··female thread part, 50··lower disk part, 51··middle cylinder part, 52··upper disk part, 53··communication hole, 54··outer cylinder, 62··gap, 63··storage chamber, 65··valve body, 66··coil spring, 67··head, 69··ball, 70··outlet, 71, 83··threaded part, 75A, 75B··fitting, 80··coupler unit, 81··pipe, 82·coupler, 93··nipple, 100·connector.

Claims

1. A grease discharge device including a pump, a discharge path for grease discharged by the operation of the pump, a relief valve provided in the discharge path for releasing the pressure in the discharge path, and a discharge port provided downstream of the relief valve to which a coupler unit formed by connecting a coupler to the tip of a hose or a pipe is connected. An attachment for a grease discharge device connectable between the discharge port and the hose or the coupler unit, or between the hose and the coupler unit connected to the hose, wherein: a pressure relief valve that releases the pressure of the grease when the pressure of the grease passing through the interior exceeds a predetermined operating pressure that is lower than the pressure at which the relief valve operates; an adjustment mechanism for adjusting the operating pressure, characterized in that the attachment for a grease discharge device comprises the above.

2. The attachment for a grease discharge device according to claim 1, further comprising a storage chamber capable of storing a predetermined amount of the grease discharged by the pressure relief valve.

3. The attachment for a grease discharge device according to claim 2, wherein the storage chamber is provided with a discharge portion for discharging grease exceeding the predetermined amount to the outside.

4. The attachment for a grease discharge device according to claim 2 or 3, wherein the storage chamber is formed in a ring shape centered on the pressure relief valve.

5. Including a through hole to which the discharge port, the hose, and the coupler unit can be respectively connected, and a communication hole for communicating the through hole and the storage chamber. The pressure relief valve includes a valve body provided in the communication hole and capable of opening and closing an outlet of the grease from the through hole, and an elastic member for biasing the valve body toward the closing side of the outlet. The attachment for a grease discharge device according to claim 2 or 3 is characterized in that it comprises the above.

6. The attachment for a grease discharge device according to claim 5, wherein the adjustment mechanism is an adjustment knob capable of adjusting the biasing force applied to the valve body by pressing the elastic member by a screw feed operation.

7. A grease discharge device including a pump, a discharge path for grease discharged by the operation of the pump, a relief valve provided in the discharge path for releasing the pressure in the discharge path, and a discharge port provided downstream of the relief valve to which a coupler unit formed by connecting a coupler to the tip of a hose or a pipe is connected. The grease discharge device characterized in that an attachment for a grease discharge device according to any one of claims 1 to 3 is connected between the discharge port and the hose or the coupler unit, or between the hose and the coupler unit connected to the hose.

8. A hose for a grease discharge device connected to the discharge port of a grease discharge device including a pump, a discharge path of grease discharged by the operation of the pump, a relief valve provided in the discharge path for releasing the pressure in the discharge path, and a discharge port provided downstream of the relief valve, a pressure relief valve that releases the pressure of the grease when the pressure of the grease discharged from the discharge port and passing through the inside exceeds a predetermined operating pressure that is lower than the pressure at which the relief valve operates, and an adjustment mechanism capable of adjusting the operating pressure.

9. A coupler unit for a grease discharge device connected to the discharge port of a grease discharge device including a pump, a discharge path of grease discharged by the operation of the pump, a relief valve provided in the discharge path for releasing the pressure in the discharge path, and a discharge port provided downstream of the relief valve, and having a coupler connected to the tip of a pipe, a pressure relief valve that releases the pressure of the grease when the pressure of the grease discharged from the discharge port and passing through the inside exceeds a predetermined operating pressure that is lower than the pressure at which the relief valve operates, and an adjustment mechanism capable of adjusting the operating pressure.

10. An attachment for a grease discharge device connectable between the discharge port and the hose or the coupler unit, or between the hose and the coupler unit connected to the hose, in a grease discharge device including a motor, a pump operated by driving of the motor, a discharge path of grease discharged by the operation of the pump, and a discharge port provided downstream of the discharge path and connected to a hose or a coupler unit having a coupler connected to the tip of a pipe, and stopping the rotation of the motor when the current value of the motor reaches a predetermined value corresponding to a predetermined discharge pressure of the grease from the discharge port. A pressure relief valve that releases the pressure of the grease when the pressure of the grease passing through the interior exceeds a predetermined operating pressure that is lower than the predetermined discharge pressure, and An adjustment mechanism capable of adjusting the operating pressure, characterized in that it comprises an attachment for a grease discharge device.

11. A grease discharge device including a motor, a pump operated by driving the motor, a discharge path of the grease discharged by the operation of the pump, a discharge port provided downstream of the discharge path, and a coupler connected to the discharge port for discharging the grease, A first discharge pressure corresponding part that releases the grease to the outside or stops the rotation of the motor when the discharge pressure of the grease in the discharge path is a predetermined first pressure, A second discharge pressure corresponding part that is provided between the discharge port and the coupler and releases the grease to the outside without supplying the grease to the coupler when the discharge pressure of the grease at the discharge port is a predetermined second pressure lower than the first pressure, Characterized in that it comprises a grease discharge device.

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