Attachments for grease discharge devices, grease discharge devices, hoses for grease discharge devices, coupler units for grease discharge devices

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 discharge device used in a grease discharge device such as a grease gun, a grease discharge device, a hose for a grease discharge device, and a coupler unit for a grease discharge device.

Background Art

[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 housed in the housing, and a pump driven by the motor. In this grease gun, when the plunger of the pump reciprocates by driving the motor, the grease in the tank is pressure-fed and discharged from the discharge port. Further, the pump is provided with a relief valve (bleed valve) that operates when the pressure in the discharge path becomes a predetermined value or more and discharges grease to the outside.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The operation using 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 the grease injection port of an external device at the tip of a pipe, sometimes referred to as an "adapter") to the tip of the hose, and discharging grease from the tip of the hose or coupler unit held by the operator to a required location. 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 may be damaged by pressure before the relief valve operates.

[0005] Therefore, the purpose of this disclosure is 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 hoses and coupler units connected to the discharge port. [Means for solving the problem]

[0006] To achieve the above objective, the first configuration of the present disclosure is an attachment for a grease discharge device, which includes a pump, a discharge passage for grease discharged by the operation of the pump, a relief valve provided in the discharge passage for releasing pressure in the discharge passage, and a discharge port provided downstream of the relief valve to which a coupler unit, which has a coupler connected to the end of a hose or pipe, is connected, and may be connectable between the discharge port and a hose or coupler unit, or between a hose and a coupler unit connected to a hose. The attachment for the grease discharge device may also 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 pressure at which the relief valve operates. The attachment for the grease dispensing device may include an adjustment mechanism that allows for adjustment of the operating pressure. To achieve the above objective, a second configuration of the present disclosure may include a grease discharge device comprising: a pump; a discharge passage for grease discharged by the operation of the pump; a relief valve provided in the discharge passage for releasing pressure in the discharge passage; and a discharge port provided downstream of the relief valve to which a coupler unit, which is formed by connecting a coupler to the end of a hose or pipe, is connected. The grease discharge device may be configured by connecting the grease discharge device attachment described in any of the first configurations between the discharge port and a hose or coupler unit, or between a hose and a coupler unit connected to a hose. To achieve the above objective, a third configuration of the present disclosure may be a hose for a grease discharge device, which is connected to the discharge port of a grease discharge device comprising a pump, a discharge passage for grease discharged by the operation of the pump, a relief valve provided in the discharge passage for releasing pressure in the discharge passage, and a discharge port provided downstream of the relief valve. A 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 that allows adjustment of the operating pressure. To achieve the above objective, the fourth configuration of this disclosure may be a coupler unit for a grease discharge device, which is connected to the discharge port of a grease discharge device comprising a pump, a discharge passage for grease discharged by the operation of the pump, a relief valve provided in the discharge passage for releasing pressure in the discharge passage, and a discharge port provided downstream of the relief valve, and a coupler is connected to the end of the pipe. A coupler unit 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 that allows adjustment of the operating pressure. To achieve the above objective, a fifth configuration of this disclosure is an attachment for a grease discharge device, which includes a motor, a pump operated by the motor, a discharge passage for grease discharged by the operation of the pump, and a discharge port provided downstream of the discharge passage to which a coupler unit, which has a coupler connected to the end of a hose or pipe, is connected, and the motor stops rotating when the motor current value reaches a predetermined value corresponding to a predetermined discharge pressure of grease from the discharge port, and may be connectable between the discharge port and a hose or coupler unit, or between a hose and a coupler unit connected to a hose. 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 a predetermined discharge pressure, and an adjustment mechanism that allows adjustment of the operating pressure. To achieve the above objective, the sixth configuration of this disclosure may include a grease discharge device comprising a motor, a pump operated by the motor, a discharge passage for grease discharged by the operation of the pump, a discharge port provided downstream of the discharge passage, and a coupler connected to the discharge port for discharging grease. The grease discharge device may include a first discharge pressure response section 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 reaches a predetermined first pressure. The grease discharge device may include a second discharge pressure response section provided between the discharge port and the coupler, which 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 lower than the first pressure. [Effects of the Invention]

[0007] According to this disclosure, when the internal pressure of a hose or coupler unit increases, the pressure can be released before the relief valve of the grease discharge device activates or the motor stops rotating. Therefore, damage to the hose or coupler unit connected to the discharge port can be effectively prevented. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view of a grease gun. [Figure 2] This is a longitudinal cross-section of the grease gun. [Figure 3] This is a partial cross-sectional view along line AA in Figure 2. [Figure 4] This is a magnified cross-sectional view of the attachment part for the grease gun. [Figure 5] This is a disassembled perspective view of a grease gun attachment. [Figure 6]This is a perspective view of a grease gun with the modified attachment installed. [Figure 7] This is a magnified cross-sectional view of the grease gun attachment portion of the modified example. [Modes for carrying out the invention]

[0009] In one embodiment of the present disclosure, it is desirable that the attachment for the grease discharge device includes a storage chamber capable of storing a predetermined amount of grease released by the pressure relief valve. This configuration allows for the temporary storage of grease released by the grease discharge attachment, thereby suppressing the scattering of grease from the activated grease discharge attachment. In one embodiment of this disclosure, it is desirable that the storage chamber be equipped with a discharge section for discharging excess grease to the outside. This configuration makes it easier for the operator to notice when the pressure relief valve on the grease discharge device attachment is activated. In one embodiment of this disclosure, it is preferable that the storage chamber is formed in a ring shape centered on a pressure relief valve. This configuration allows for a larger storage chamber volume, enabling sufficient storage of the released grease.

[0010] In one embodiment of the present disclosure, the attachment for the grease discharge device preferably includes a through hole to which a discharge port, a hose, and a coupler unit can be connected, and a communication hole connecting the through hole and a storage chamber, and the pressure relief valve preferably includes a valve body provided in the communication hole and capable of opening and closing the outlet of grease from the through hole, and an elastic member that biases the valve body toward the outlet closing side. This configuration allows for a compact design of the attachment for the grease dispensing device. In one embodiment of the present disclosure, the adjustment mechanism is preferably an adjustment knob that can adjust the biasing force on the valve body by pressing an elastic member with a screw-feed operation. This configuration allows for easy adjustment of the operating pressure of the grease dispensing attachment.

Embodiment

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

[0012] A switch 8 is housed in the grip portion 4. The switch 8 includes 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 on / off the light 10 is provided on the upper surface of the front portion of the grip portion 4. A lock-on button 12 for maintaining the pushed-in state of the trigger 9 is provided on the grip portion 4 in front of the trigger 9. A lock-off button 13 for restricting the pushing-in of the trigger 9 is provided in front of the trigger 9 below the lock-on button 12. Inside the motor housing section 3, the motor 14 is housed with its output shaft 15 facing forward. A gear housing 16 is assembled in front of the motor 14. The gear housing 16 houses a reduction mechanism 17. The reduction mechanism 17 reduces the rotation of the output shaft 15 and outputs it to the spindle 18. A crank mechanism 19 is provided on the front side of the spindle 18. The crank mechanism 19 converts the rotation of the spindle 18 into vertical movement of the slider 20. A downward-facing plunger 21 is integrally provided on the slider 20.

[0013] A cylindrical front holder 22 opening to the rear is formed at the lower part of the gear housing 16. The tank 23 is connected to the front holder 22 from the rear. A rear holder 24 protruding downward is provided behind the front holder 22 at the lower part of the motor housing 3. The rear holder 24 supports the tank 23 in the front-rear direction. A pump 25 is provided inside 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 is formed between the upper cylinder portion 26 and the lower cylinder portion 27, communicating with the inside of the front holder 22. The plunger 21 moves up and down by passing 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 of the lower cylinder portion 27. A vertical discharge passage 29 is formed inside the lower cylinder portion 27. The vertical discharge passage 29 communicates with the gap 28, and the plunger 21 is inserted through it.

[0014] A horizontal discharge passage 30, which communicates with the vertical discharge passage 29, is formed in the lower cylindrical portion 27, facing forward. The vertical discharge passage 29 and the horizontal discharge passage 30 form a grease discharge passage. A check valve 31 is provided at the lower end of the vertical discharge passage 29. The check valve 31 is provided to prevent backflow of grease in the vertical discharge passage 29. As shown in Figure 3, a connecting passage 30a is formed in communication with the lateral discharge passage 30, opening to the right side of the front holder 22. A relief valve 32 is provided in the connecting passage 30a. The relief valve 32 comprises a valve bolt 33 and a valve cover 34. The valve bolt 33 is screwed into the connecting passage 30a. The valve cover 34 is attached to the head of the valve bolt 33, which protrudes from the right side 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 axially in communication with the connecting passage 30a and then opens radially at the head of the valve bolt 33 as shown by the dotted line. The valve pin 33b is movable in the axial direction, holding the ball 33c at its tip. The coil spring 33d biases the valve pin 33b to the closed position shown in Figure 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 connect 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 flowing into the connecting passage 30a presses against the ball 33c against the biasing force of the coil spring 33d, moving the valve pin 33b to the open position that opens the relief passage 33a. As a result, the grease in the relief passage 33a flows out through the groove 33f from the head of the valve pin 33b, thus releasing the pressure.

[0016] A discharge port 35, which forms a lateral discharge passage 30, protrudes forward from the front of the front holder 22. A fitting 75A, provided at the rear end of the hose 36, is screwed into 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 penetrates the rear holder 24 from the rear, and its front end is connected to the front holder 22. Inside the tank 23, a rod 37 with a piston 38 at its front end is provided so as to be movable in the front-rear direction. Inside the tank 23, a coil spring 39 is provided to bias the piston 38 forward. When 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 biasing force of the coil spring 39, and supplied to the pump 25.

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

[0018] The communication hole 53 is formed coaxially within the central cylinder portion 51 and spans the connecting portion 41, the lower disc portion 50, and the upper disc 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 circular cross-section hole that communicates with the longitudinal center of the through hole 45 within the connecting portion 41 and extends upward. The medium diameter hole portion 58 is a circular cross-section hole with a larger diameter than the small diameter hole portion 57, connected coaxially with the small diameter hole portion 57 within the connecting portion 41, and extends upward through the lower disc portion 50 and the central cylinder portion 51. The large diameter hole portion 59 is a circular cross-section hole with a larger diameter than the medium diameter hole portion 58, connected coaxially with the medium diameter hole portion 58 within the central cylinder portion 51, and opens to the upper surface through the upper disc 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 central cylinder portion 51 in the diametrical direction and communicates with the medium-diameter hole portion 58. The outer cylinder 54 is fitted over the lower disc portion 50 and the upper disc portion 52 and rests on the receiving portion 47 of the connecting portion 41. An O-ring 55 is pressed against the lower inner circumference of the lower disc portion 50, sealing the space between the lower disc portion 50 and the outer cylinder 54 around its entire circumference. The outer cylinder 54 and the upper disc portion 52 are not in contact, and a ring-shaped discharge port 62 is formed between them around its entire circumference. Thus, a ring-shaped grease storage chamber 63 is formed inside the outer cylinder 54, surrounded by the lower disc portion 50, the middle cylinder portion 51, the upper disc 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 housed within the medium-diameter hole 58 of the communication hole 53. The pressure relief valve 43 comprises a valve body 65 and a coil spring 66. The valve body 65 is a shaft that extends vertically, with a large-diameter head 67 integrally formed at its lower end. A circular recess 68 opening downwards is formed in the center of the lower surface of the head 67. A ball 69 is fitted into the circular recess 68, with its lower part protruding from the lower surface of the head 67. An outlet 70 of the small-diameter hole 57 opens at the bottom surface of the medium-diameter hole 58. The ball 69 protruding from the lower surface of the head 67 can close the outlet 70. The coil spring 66 is externally mounted on the valve body 65 within the medium-diameter hole 58, with its lower end in contact with the upper surface of the head 67.

[0020] The adjustment knob 44 has a threaded portion 71 at the center of its lower surface. The threaded portion 71 protrudes downward and is screwed into the female threaded portion 61 of the large-diameter hole 59. The upper end of the coil spring 66 is in contact with the lower surface of the threaded portion 71. Therefore, the valve body 65 is biased downward by the coil spring 66, pressing the ball 69 against the outlet 70 of the small-diameter hole 57. This pressing force can be adjusted by rotating the adjustment knob 44 to change the amount of threading in the screw portion 71 and thereby changing the shaft length of the coil spring 66. This allows the operating pressure at which the valve body 65 moves upward against the biasing force of the coil spring 66 and opens the outlet 70 of the small-diameter hole 57 to be adjusted, for example, in the range of 15 to 20 MPa. This operating pressure is lower than the operating pressure of the relief valve 32 provided in the grease gun 1 (for example, 80 MPa).

[0021] The coupler unit 80 comprises a pipe 81 and a coupler 82 connected to its front end. The pipe 81 has threaded portions 83, 83 at both the front and rear ends. The coupler 82 comprises 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, while the others are made of metal such as iron. The head 84 is sleeve-shaped and connected to the pipe 81 by screwing the threaded portion 83 at the front end of the pipe 81 into it. The cap 85 is sleeve-shaped and connected to the head 84 by screwing the threaded portion at the front end of the head 84 into it. The ball 86 is held movably within the front end of the head 84 and can open and close the valve seat 91 inside the head 84. Inside the cap 85, in front of the head 84, are housed in the order of a coil spring 87, a seal sleeve 88, a rigid sleeve 89, and a chuck jaw 90. A stopper 92 is provided on the inner circumference of the front end of the cap 85 to prevent the chuck jaw 90 from coming off. The coil spring 87 is positioned between the ball 86 and the seal sleeve 88 and biases the ball 86 to the closed position, forming a check valve together with the ball 86. The rigid sleeve 89 contacts the chuck jaw 90 to position the seal sleeve 88. The chuck jaws 90 are elastically expandable and housed at the front end of the cap 85, and are normally biased to retract.

[0022] Therefore, under normal conditions, the valve seat 91 of the coupler 82 is closed by a ball 86 biased by a coil spring 87. When supplying grease, a nipple 93, which is a grease inlet provided on external equipment such as agricultural machinery, is inserted into the tip of the cap 85. Then, as shown by the dashed line in Figure 4, the ball-shaped tip 94 of the nipple 93 pushes open the chuck jaws 90 and enters the chuck jaws 90, contacting the front end surface of the seal sleeve 88. When the chuck jaws 90 overcome the tip 94 of the nipple 93 relative to it, they contract and elastically grip the tip 94. Thus, the nipple 93 is connected to the coupler 82, and the internal passage 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 fitting 75B, which is provided on the front end of the hose 36, into one female threaded portion 46 of the through hole 45 of the connecting portion 41. The other female threaded portion 46 of the through hole 45 is screwed into the threaded portion 83 of the pipe 81 of the coupler unit 80. As a result, 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 inside of the hose 36 and 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. The controller 6, detecting the signal from the switch 8, then supplies drive current to the motor 14, causing the output shaft 15 to rotate. The rotation of the output shaft 15 is reduced 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 up-and-down movement of the slider 20, causing the plunger 21 to reciprocate up and down. Therefore, in the pump 25, when the plunger 21 reaches top dead center, grease flows into the vertical discharge passage 29 of the lower cylinder 27 from the gap 28 between the upper cylinder 26 and the lower cylinder 27. Then, when the plunger 21 moves to bottom dead center, the grease pushed downwards in the vertical discharge passage 29 flows into the horizontal discharge passage 30 and is discharged into the hose 36 via the discharge port 35. This discharge operation is repeated in accordance with the reciprocating movement of the plunger 21.

[0024] The grease that has passed through hose 36 passes through through hole 45 at connection part 41 of attachment 40 and then flows into pipe 81 of coupler unit 80. The grease supplied from pipe 81 to coupler 82 presses ball 86 as it passes through head 84, separating it from valve seat 91, and flows into seal sleeve 88. If coupler 82 is connected to nipple 93 as described above, the grease is supplied to external equipment via nipple 93.

[0025] Then, 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, opening the outlet 70 of the small-diameter hole 57. As a result, the grease in the through hole 45 flows from the small-diameter hole 57 to the medium-diameter hole 58 and into the storage chamber 63 via the through hole 60. By releasing the pressure in the through hole 45 in this way, excessive pressure rise in the hose 36 and coupler unit 80 is prevented. Therefore, the risk of damage to the hose 36 and coupler unit 80 is reduced. In addition, because the grease is stored 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 disc portion 52 and the outer cylinder 54. Therefore, the worker gripping the coupler unit 80 will be more likely to notice that the pressure relief valve 43 of the attachment 40 has been activated. Furthermore, after completing the work with the grease gun 1, loosening the adjustment knob 44 on the attachment 40 reduces the pressure on the coil spring 66, allowing the pressure from the grease filled in the hose 36 and coupler unit 80 to be released from the communication hole 53 into the storage chamber 63. This makes it easier to remove the coupler unit 80 from the nipple 93.

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

[0027] The attachment 40 is equipped 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 equipped with an outlet 62 (an example of a discharge section) for discharging excess grease to the outside. Therefore, it becomes easier for the worker to notice when the pressure relief valve 43 of attachment 40 is activated. The storage chamber 63 is formed in a ring shape with the pressure relief valve 43 at its center. Therefore, the volume of the storage chamber 63 can be made larger, and the released grease can be sufficiently stored.

[0028] The attachment 40 includes through holes 45 to which the hose 36 and the coupler unit 80 can be connected, and a communication hole 53 that connects the through hole 45 to the storage chamber 63. The pressure relief valve 43 includes a valve body 65 provided in the communication hole 53 and capable of opening and closing the grease outlet 70 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 made compact. The adjustment mechanism is an adjustment knob 44 that allows adjustment of the biasing force applied to the valve body 65 by pressing the coil spring 66 with a screw-in operation. Therefore, the operating pressure of attachment 40 can be easily adjusted.

[0029] The following describes examples of changes to this disclosure. In the above embodiment, the attachment is connected between the hose and the coupler unit, but the attachment may also be connected between the discharge port and the hose or coupler unit connected to the discharge port. Figures 6 and 7 show an example in which the attachment 40 is connected between the discharge port 35 and the hose 36. Here, the second cylinder 102 of the connector 100, which is screwed onto the tip of the discharge port 35, is screwed into one of the female threaded portions 46 of the through hole 45 of the connecting portion 41. The fitting 75A, which is provided at the rear end of the hose 36, is screwed into the other female threaded portion 46. A coupler 82 is connected to the front end of the hose 36.

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

[0031] In connector 100, the threaded portion 107 at the rear end of the first cylinder 101 is screwed into the discharge port 35. The cylinder joint 103, which passes through the second cylinder 102, is screwed into the threaded portion 106 at the front end of the first cylinder 101. Thus, connector 100 is coaxially connected to the discharge port 35. In this state, the O-ring 105 seals the space between the discharge port 35 and the first cylinder 101. The O-ring 109 seals the space between the first cylinder 101 and the second cylinder 102. The threaded portion 110 of the second cylinder 102 is screwed into the female threaded portion 46 of the through hole 45 of the connecting portion 41, thereby connecting it to the attachment 40. In this case, because the diameter of the threaded portion 110 of the second cylinder and the joint 75A are different, the thickness of the connecting portion 41 in the vertical direction is greater than in the previous embodiment, but the other configurations and operation of the attachment 40 are the same as in the above embodiment. However, the connector configuration is not limited to the above example; one of the first or second cylinders may be omitted, and only one cylinder may be used to connect the discharge port and the connecting part. Depending on the shape 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 those that are provided separately from the hose and coupler unit and connected by screwing, as in the examples above. For example, the attachment can be integrated with the hose to create a hose with an attachment (a hose for a grease discharge device relating to the third configuration). In this case, the attachment may be located at the front end of the hose or in the middle of the hose. Possible methods for integrating the attachment with the hose include fixing the connecting part to the hose with screws or other fasteners, or integrally forming the connecting part with the hose. Similarly, the attachment can be integrated with the coupler unit to form a coupler unit with an attachment (a coupler unit for a grease discharge device according to the fourth configuration). In this case, the attachment may be located between the pipe and the coupler, or at the rear end or intermediate part of the pipe. To integrate the attachment and the coupler unit, possible methods include fixing the connecting part to the pipe or coupler with screws, or integrally forming the connecting part with the pipe or coupler.

[0033] The structure of the attachment itself is not limited to the above-described embodiment. The storage chamber of the grease reservoir does not have to be ring-shaped. The volume of the storage chamber can be increased or decreased as appropriate. The grease discharge port from the storage chamber is not limited to the discharge port in the above embodiment. For example, the space between the upper disc and the outer cylinder can also be sealed with an O-ring or the like, and one or more through holes communicating with the storage chamber can be formed in the upper disc or outer cylinder to serve as a discharge port. The discharge port may also be provided on the lower surface of the attachment. However, it is possible to omit the storage chamber and configure the system to immediately discharge the released grease to the outside. The pressure relief valve may have a hemispherical projection integrally provided on the lower surface of the valve body instead of a ball on the valve body. The coil spring may be provided not just once, but in multiples (for example, in a double configuration). The elastic component is not limited to coil springs; disc springs and other types can also be used. The communication holes and pressure relief valves may be installed horizontally rather than vertically. The adjustment mechanism can also be modified as appropriate depending on the position and structure of the pressure relief valve. For example, if the pressure relief valve is positioned horizontally, the adjustment knob can also be positioned horizontally. The adjustment mechanism is not limited to an adjustment knob. For example, the adjustment mechanism can also be a set screw with a hexagonal socket that can be rotated. The operating pressure that the adjustment mechanism can adjust is not limited to the above embodiment and can be changed as appropriate. The connection between the attachment and the hose and coupler unit is not limited to screw-in connections; other types of connections, such as push-in connections, can also be used.

[0034] The grease dispensing device is not limited to the grease gun of the above embodiment. For example, a brushless motor can also be used. The grease dispensing device can also be configured such that the tank is supported in the vertical direction rather than the front-to-back direction, and the motor housing and grip sections are formed in the vertical direction. Multiple battery packs may be used. The grease dispensing device may be an AC-powered device that does not use battery packs. The grease discharge device is not limited to one that relieves pressure in the discharge passage using a relief valve. For example, instead of a relief valve, a controller may monitor the current flowing to 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 a hose or connector, or between a hose and a coupler unit connected to the hose, corresponds to the fifth configuration of this disclosure.

[0035] Furthermore, the following disclosure can also be extracted from the above embodiments as a grease dispensing device. This corresponds to the sixth configuration of this disclosure. A grease dispensing device comprising a motor, a pump operated by the motor, a discharge passage for grease discharged by the operation of the pump, a discharge port provided downstream of the discharge passage, and a coupler connected to the discharge port for dispensing grease, When the discharge pressure of grease in the discharge passage reaches a predetermined first pressure (e.g., 80 MPa), a first discharge pressure response unit (e.g., relief valve 32 or controller 6) releases the grease to the outside or stops the rotation of the motor. A grease discharge device characterized by comprising: a second discharge pressure response section (e.g., attachment 40) provided between the discharge port and the coupler, which, when the discharge pressure of grease at the discharge port is a predetermined second pressure (e.g., 15-20 MPa) lower than the first pressure, releases the grease to the outside without supplying it to the coupler. [Explanation of symbols]

[0036] 1. Grease gun, 2. Main housing, 3. Motor housing, 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. Attachment for grease gun, 41. Connecting section, 42. Grease reservoir Part 43... Pressure relief valve, 44... Adjustment knob, 45... Through hole, 46... Female threaded part, 50... Lower disc part, 51... Middle cylinder part, 52... Upper disc 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 parts, 75A, 75B... Fittings, 80... Coupler unit, 81... Pipe, 82... Coupler, 93... Nipple, 100... Connector.

Claims

1. A grease dispensing device comprising a pump, a discharge passage for grease discharged by the operation of the pump, a relief valve provided in the discharge passage for releasing pressure in the discharge passage, and a discharge port provided downstream of the relief valve to which a coupler unit, which has a coupler connected to the end of a hose or pipe, is connected, wherein an attachment for a grease dispensing device is connectable between the discharge port and the hose or the coupler unit, or between the hose and the coupler unit connected to the hose, 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 attachment for a grease dispensing device, characterized by comprising an adjustment mechanism capable of adjusting the operating pressure.

2. The attachment for a grease discharge device according to claim 1, characterized in that it comprises a storage chamber capable of storing a predetermined amount of grease released by the pressure relief valve.

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

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

5. The attachment for a grease discharge device according to claim 2 or 3, comprising a through hole into which the discharge port, the hose, and the coupler unit can each be connected, and a communication hole connecting the through hole and the storage chamber, wherein the pressure relief valve comprises a valve body provided in the communication hole and capable of opening and closing the outlet of grease from the through hole, and an elastic member that biases the valve body toward the closing side of the outlet.

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

7. A grease discharge device comprising a pump, a discharge passage for grease discharged by the operation of the pump, a relief valve provided in the discharge passage for releasing pressure in the discharge passage, and a discharge port provided downstream of the relief valve to which a coupler unit, which consists of a hose or pipe with a coupler connected to the end, is connected, A grease dispensing device characterized by connecting an attachment for a grease dispensing device according to any one of claims 1 to 3 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 grease discharge device hose connected to the discharge port of a grease discharge device comprising a pump, a discharge passage for grease discharged by the operation of the pump, a relief valve provided in the discharge passage for releasing pressure in the discharge passage, and a discharge port provided downstream of the relief valve, A pressure relief valve 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. A hose for a grease discharge device, characterized by comprising an adjustment mechanism capable of adjusting the operating pressure.

9. A grease discharge device coupler unit is connected to the discharge port of a grease discharge device comprising a pump, a discharge passage for grease discharged by the operation of the pump, a relief valve provided in the discharge passage for releasing pressure in the discharge passage, and a discharge port provided downstream of the relief valve, and a coupler is connected to the end of the pipe, A pressure relief valve 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. A coupler unit for a grease discharge device, characterized by comprising an adjustment mechanism capable of adjusting the operating pressure.

10. A grease dispensing device comprising a motor, a pump operated by the drive of the motor, a discharge passage for grease discharged by the operation of the pump, and a discharge port provided downstream of the discharge passage to which a coupler unit, which has a coupler connected to the end of a hose or pipe, is connected, wherein the motor stops rotating when the current value of the motor reaches a predetermined value corresponding to a predetermined discharge pressure of grease from the discharge port, and an attachment for a grease dispensing device that can be connected between the discharge port and the hose or the coupler unit, or between the hose and the coupler unit connected to the hose, 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, An attachment for a grease dispensing device, characterized by comprising an adjustment mechanism capable of adjusting the operating pressure.

11. A grease dispensing device comprising a motor, a pump operated by the drive of the motor, a discharge passage for grease discharged by the operation of the pump, a discharge port provided downstream of the discharge passage, and a coupler connected to the discharge port for dispensing grease, A first discharge pressure response unit that, when the discharge pressure of grease in the discharge passage reaches a predetermined first pressure, releases the grease to the outside or stops the rotation of the motor, A second discharge pressure response unit is provided between the discharge port and the coupler, and when the discharge pressure of the grease at the discharge port is a predetermined second pressure lower than the first pressure, the grease is released to the outside without being supplied to the coupler. A grease dispensing device characterized by comprising the following:

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