Quick Coupler

Abstract

To provide a quick coupler with high safety and easy handling.SOLUTION: A quick coupler 1 comprises a fixing member 2 having a first hook 3 engageable with a first pin of an attachment, a movable member 4 having a second hook 5 engageable with a second pin of the attachment and rotatably provided on the fixing member 2, a hydraulic cylinder 6 having one axial end 6a fixed to the fixing member 2 and the other axial end 6b fixed to the movable member 4, and having a spring biasing it in the extension direction, and a locking member 7 arranged on the fixing member 2 and locking the first hook 3 in a state where the first pin is engaged. The second hook 5 has a barbed portion at its tip.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a quick coupler used in a work vehicle. [Background technology]

[0002] A work vehicle can be fitted with interchangeable attachments, such as a cutter, breaker, or fork. To facilitate attachment replacement, the attachment is attached to the work vehicle via a quick coupler. The quick coupler connects the arm pin and link pin of the work vehicle with the first pin and second pin of the attachment.

[0003] For example, Patent Document 1 describes a quick coupler that includes a coupler body, a locking member, a second hook, a hydraulic cylinder, and a connecting pin. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6178509 Summary of the Invention [Problem to be solved by the invention]

[0005] Quick couplers are equipped with a safety function that prevents the attachment from falling off in an emergency, such as when hydraulic power is cut off. Conventional quick couplers have a safety function that requires the operator to manually attach a safety pin. To reduce the amount of work required and ensure the safety of the operator, it is desirable for the safety function to function without the need for manual intervention by the operator.

[0006] In addition, the distance between the first pin and the second pin varies depending on the type of attachment. It is desirable for the quick coupler to be applicable to various attachments. Furthermore, it is desirable for the quick coupler to be small so as not to interfere with work when working on a work vehicle.

[0007] An object of the present invention is to provide a quick coupler that is highly safe and easy to handle. [Means for solving the problem]

[0008] According to the present disclosure, there is provided a quick coupler comprising: a fixed member having a first hook with which a first pin of an attachment of a work vehicle can engage; a movable member having a second hook with which a second pin of the attachment can engage and rotatably mounted on the fixed member; a hydraulic cylinder having one axial end fixed to the fixed member and the other axial end fixed to the movable member and having a spring that biases in an extension direction; and a locking member that is disposed on the fixed member and locks when the first pin is engaged with the first hook, wherein the second hook has a barb at its tip. [Effects of the Invention]

[0009] According to the present disclosure, a quick coupler that is highly safe and easy to handle can be provided. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view of a work vehicle equipped with a quick coupler according to an embodiment, as viewed from the left front. [Figure 2] FIG. 2 is a side view showing a part of a work vehicle to which a quick coupler according to an embodiment is attached. [Figure 3] FIG. 3 is a perspective view of a part of a work vehicle equipped with a quick coupler according to an embodiment, as viewed from the left front. [Figure 4] FIG. 4 is a side view of the quick coupler according to the embodiment. [Figure 5]FIG. 5 is a side cross-sectional view of the quick coupler according to the embodiment. [Figure 6] FIG. 6 is an enlarged view of the second hook. [Figure 7] FIG. 7 is a perspective view of a hydraulic cylinder. [Figure 8] FIG. 8 is a cross-sectional view of a hydraulic cylinder. [Figure 9] FIG. 9 is a side cross-sectional view of the quick coupler according to the embodiment. [Figure 10] FIG. 10 is a side cross-sectional view of the quick coupler according to the embodiment. [Figure 11] FIG. 11 is a side cross-sectional view of the quick coupler according to the embodiment. [Figure 12] FIG. 12 is a perspective view showing the locking member. [Figure 13] FIG. 13 is a schematic diagram showing a locking member. [Figure 14] FIG. 14 is a schematic diagram showing a locking member. [Figure 15] FIG. 15 is a side cross-sectional view of the quick coupler according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings, but the present invention is not limited thereto. The components of the embodiments described below can be combined as appropriate. In addition, some components may not be used.

[0012] [Work vehicle] FIG. 1 is a perspective view of a work vehicle equipped with a quick coupler according to an embodiment, as viewed from the left front. FIG. 2 is a side view showing a portion of a work vehicle equipped with a quick coupler according to an embodiment. FIG. 3 is a perspective view of a portion of a work vehicle equipped with a quick coupler according to an embodiment, as viewed from the left front. The work vehicle is, by way of example, a hydraulic excavator 100, but is not limited to this. The hydraulic excavator 100 includes an arm 101, a link member 102, an arm pin 103 provided at the tip of the arm 101, and a link pin 104 provided at the tip of the link member 102. A quick coupler 1 is attached to the hydraulic excavator 100 via the arm pin 103 and the link pin 104. An attachment 110 is attached to the quick coupler 1 via a first pin 111 and a second pin 112. In FIGS. 1 and 2, a bucket is attached as an example of the attachment 110. The attachment 110 is not limited to a bucket, but may be various members such as a cutter, a breaker, or a fork.

[0013] [Quick Coupler] The quick coupler 1 facilitates the attachment and detachment of the attachment 110. The quick coupler 1 is connected to the tip of the arm 101 via an arm pin 103. The quick coupler 1 is connected to the tip of the link member 102 via a link pin 104. The attachment 110 is replaceably mounted on the quick coupler 1 via a first pin 111 and a second pin 112 of the attachment 110.

[0014] Fig. 4 is a side view of a quick coupler according to an embodiment. Fig. 5 is a side cross-sectional view of a quick coupler according to an embodiment. The quick coupler 1 has a fixed member 2, a first hook 3, a movable member 4, a second hook 5, a hydraulic cylinder 6, and a locking member 7. The fixed member 2 and the movable member 4 are rotatably connected. The hydraulic cylinder 6 is arranged to extend and retract across the fixed member 2 and the movable member 4. The fixed member 2 has the first hook 3. The movable member 4 has the second hook 5.

[0015] 2, the fixed member 2 is connected to an arm 101 and a link member 102. More specifically, the fixed member 2 is connected to the tip of the arm 101 via an arm pin 103. The fixed member 2 is connected to the tip of the link member 102 via a link pin 104.

[0016] As shown in Figure 3, the fixing member 2 has a main body portion 21R located on the right side when viewed from the driver's seat of the hydraulic excavator 100, a main body portion 21L located on the left side, and a connecting portion 28 that connects the main body portion 21R and the main body portion 21L. The connecting portion 28 extends along the axial direction of the arm pin 103 and the link pin 104. The main body portion 21R and the main body portion 21L are formed in a plate shape. The main body portion 21R and the main body portion 21L are arranged facing each other. When it is not necessary to distinguish between the main body portion 21R and the main body portion 21L, they will be described as the main body portion 21.

[0017] As shown in FIG. 4, the main body 21 is provided with an arm pin support hole 22 that penetrates the main body 21. An arm pin 103 is inserted into the arm pin support hole 22. The arm pin 103 penetrates the main body 21R and the main body 21L. The main body 21 is provided with a link pin support hole 23 that penetrates the main body 21. A link pin 104 is inserted into the link pin support hole 23. The link pin 104 penetrates the main body 21R and the main body 21L. The arm pin support hole 22 and the link pin support hole 23 are arranged at a distance from each other in the extension / retraction direction of the hydraulic cylinder 6.

[0018] As shown in Figure 5, the main body 21 is provided with an elongated hole 24 that penetrates the main body 21. The elongated hole 24 is formed in an elliptical shape that is long in the extension / retraction direction of the hydraulic cylinder 6. The cylinder pin 68 of the hydraulic cylinder 6 slidably engages with the elongated hole 24. The elongated hole 24 is located in the middle of the main body 21. The elongated hole 24 is located on the first hook 3 side of the arm pin support hole 22 and the link pin support hole 23 in the main body 21.

[0019] 4, the main body 21 is provided with a lock pin support hole 25 that penetrates the main body 21. A lock pin 79 of the locking member 7 is inserted into the lock pin support hole 25. The lock pin support hole 25 is located on the main body 21 closer to the first hook 3 than the elongated hole 24.

[0020] As shown in FIG. 3, the first hook 3 is provided on the main body 21 on the opposite side to the arm pin support hole 22 and the link pin support hole 23. The first hook 3 extends between the main body 21R and the main body 21L along the axial direction of the arm pin 103 and the link pin 104. The first hook 3 is engageable with the first pin 111 (see FIG. 2) of the attachment 110. As shown in FIG. 4, the first hook 3 has a recess 31 that opens in the direction opposite to the second hook 5. The first pin 111 (see FIG. 2) of the attachment 110 is hooked into the recess 31. The recess 31 has an opening larger than the diameter of the first pin 111. The first hook 3 has a tapered portion that contacts the first pin 111 hooked on the first hook 3. The tapered portion is referred to as an inclined surface 31b. The inclined surface 31b is inclined so that the recess 31 widens toward the tip 3a of the first hook 3.

[0021] 2, the movable member 4 is connected to a link member 102. More specifically, the movable member 4 is connected to the tip of the link member 102 via a link pin 104.

[0022] As shown in Fig. 3, the movable member 4 has a main body 41R located on the right side as viewed from the driver's seat of the hydraulic excavator 100, a main body 41L located on the left side, and a wall 48 connecting the main body 41R and the main body 41L. The main body 41R and the main body 41L are formed in a plate shape. The main body 41R and the main body 41L are disposed opposite each other. When it is not necessary to distinguish between the main body 41R and the main body 41L, they will be described as the main body 41.

[0023] As shown in Figure 5, the movable member 4 has a main body 41, a rod pin support hole 42 that penetrates the main body 41, and a link pin support hole 43 that penetrates the main body 41. A rod pin 66 of the hydraulic cylinder 6 is inserted into the rod pin support hole 42. The rod pin 66 penetrates the main body 41R and the main body 41L. A link pin 104 is inserted into the link pin support hole 43. The link pin 104 penetrates the main body 41R and the main body 41L.

[0024] As shown in FIG. 4 , the movable member 4 is rotatable relative to the fixed member 2. More specifically, the movable member 4 is rotatable relative to the fixed member 2 around the link pin 104 inserted through the link pin support hole 43. When the movable member 4 rotates relative to the fixed member 2, the distance between the second hook 5 and the first hook 3 changes. The distance between the second hook 5 and the first hook 3 can be, for example, in the range of 180 mm to 300 mm. In the example shown in FIG. 4 , when the movable member 4 is in the position indicated by the solid line, the distance between the second hook 5 and the first hook 3 is maximum. When the movable member 4 is in the position indicated by the dashed line, the distance between the second hook 5 and the first hook 3 is minimum.

[0025] As shown in FIG. 3, the second hook 5 is provided on the main body 41 on the side opposite the link pin support hole 43. The second hook 5 extends between the main body 41R and the main body 41L along the axial direction of the link pin 104. The second hook 5 is engageable with a second pin 112 (see FIG. 2) of the attachment 110. As shown in FIG. 4, the second hook 5 is provided on the side opposite the opening direction of the first hook 3. The second hook 5 has a recess 51 that opens in the opposite direction from the first hook 3. The second pin 112 (see FIG. 2) of the attachment 110 is hooked into the recess 51. The recess 51 has an opening larger than the diameter of the second pin 112.

[0026] FIG. 6 is an enlarged view of the second hook 5. The recess 51 has a curved surface 51a, an inclined surface 51b, and an inclined surface 51c. The curved surface 51a is arc-shaped with a diameter larger than the diameter of the second pin 112 of the attachment 110 when viewed in the axial direction of the second pin 112. The inclined surface 51b is an inclined surface continuing from the tip of the curved surface 51a. The inclined surface 51b is the portion that contacts the second pin 112 hooked on the second hook 5 and is tapered. The inclined surface 51b is inclined so that the recess 51 widens as it moves away from the tip of the curved surface 51a. The inclined surface 51c is inclined to the tip of the inclined surface 51b. The inclined surface 51c is inclined in a different direction from the inclined surface 51b. The inclined surface 51c is inclined so that the recess 51 narrows as it moves away from the tip of the inclined surface 51b. The inclined surface 51c forms an acute angle with respect to a line connecting the rotation center of the movable member 4 and the tip of the inclined surface 51b, which is the base end of the return portion. The inclined surface 51c forms an acute angle with respect to a line connecting the center of the link pin 104, which is the rotation center of the movable member 4, and the tip of the inclined surface 51b. The inclined surface 51c functions as a return portion of the recess 51. The provision of such a return portion prevents the second pin 112 from falling out of the recess 51 even in an emergency, such as when the hydraulic power is cut off.

[0027] FIG. 7 is a perspective view of the hydraulic cylinder. The hydraulic cylinder 6 is a cylinder having a spring that constantly biases it in the extension direction. The hydraulic cylinder 6 is connected to the hydraulic system of the hydraulic excavator 100 via a flow path 6VB and a hydraulic supply pipe 6L that are connected to the internal space of the cylinder 61. The hydraulic cylinder 6 expands and contracts in the axial direction by hydraulic pressure supplied from the hydraulic system. The hydraulic cylinder 6 is equipped with a check valve 6VC. The check valve 6VC is a check valve that prevents the movement of hydraulic oil. The check valve 6VC holds the quick coupler 1 in the locked position.

[0028] 8 is a cross-sectional view of a hydraulic cylinder. The hydraulic cylinder 6 includes a cylinder 61, a rod 62 arranged so as to be movable forward and backward relative to the cylinder 61, a first spring 63, and a second spring 64. One end 6a of the hydraulic cylinder 6 is located in the cylinder 61, and the other end 6b is located in the rod 62. As shown in FIG. 5, one end 6a of the hydraulic cylinder 6 in the extension / retraction direction is fixed to the fixed member 2, and the other end 6b is fixed to the movable member 4.

[0029] As shown in FIG. 8 , the first spring 63 is disposed between one end 6a and the wall portion 6c in a compressed state. The first spring 63 urges the hydraulic cylinder 6 in the extension direction. The first spring 63 urges the wall portion 6c in a direction away from the one end 6a. The first spring 63 is a coil spring. The second spring 64 is disposed between the wall portion 6c and the other end 6b in a compressed state. The second spring 64 urges the hydraulic cylinder 6 in the extension direction. The second spring 64 urges the other end 6b in a direction away from the wall portion 6c. The second spring 64 is a coil spring. The first spring 63 and the second spring 64 constantly apply an extension force to the hydraulic cylinder 6. The first spring 63 and the second spring 64 have an extension force sufficient to support the weight of the second hook 5 and the weight of the hydraulic cylinder 6.

[0030] The other end 6b is formed with a rod pin support hole 65. A rod pin 66 (see FIG. 5) is inserted into the rod pin support hole 65. As shown in FIG. 5, the rod pin 66 is inserted into the rod pin support hole 42 of the main body 41 of the movable member 4. When the movable member 4 rotates relative to the fixed member 2, the hydraulic cylinder 6 rotates around the rod pin 66.

[0031] As shown in FIG. 7, a support portion 67 is provided in the middle portion of the cylinder 61. The support portion 67 is formed in a cylindrical shape. The support portion 67 is provided on the outer periphery of the middle portion of the cylinder 61. The support portion 67 has a support hole 671 through which the middle portion of the cylinder 61 is inserted. A cylinder pin 68 and a protrusion 69 are provided on the outer periphery of the support portion 67. The support portion 67, the cylinder pin 68, and the protrusion 69 are formed integrally.

[0032] 9 is a side cross-sectional view of the quick coupler according to the embodiment. The cylinder pin 68 is arranged from the outer periphery of the support portion 67 toward the side. The cylinder pin 68 slidably engages with the elongated hole 24 formed in the main body portion 21 of the fixed member 2. When the cylinder 61 slides, the cylinder pin 68 slides inside the elongated hole 24 formed in the main body portion 21 of the fixed member 2. The cylinder 61 is slidable relative to the fixed member 2 by the length of the elongated hole 24.

[0033] The protrusion 69 is formed in a convex shape from the outer periphery of the support portion 67 toward the first hook 3 side. The protrusion 69 has a curved surface 69a. The curved surface 69a is curved convexly toward the first hook 3 side. The curved surface 69a comes into contact with a curved surface 73 of the locking member 7. The protrusion 69 slides in conjunction with the cylinder pin 68. When the protrusion 69 presses the locking member 7 with the curved surface 69a, the locking position is reached, and when the pressure is released, the locking position is reached.

[0034] When the second pin 112 of the attachment 110 comes into contact with the second hook 5, a reaction force is generated. The reaction force causes the cylinder 61 to slide in the extension direction, causing the locking member 7 to move from the unlocked position to the locked position. When the second pin 112 moves away from the second hook 5, the cylinder 61 slides in the contraction direction, causing the locking member 7 to move from the locked position to the unlocked position.

[0035] The hydraulic cylinder 6 is supported by a rod pin 66 and a cylinder pin 68 and changes its position relative to the fixed member 2.

[0036] Figure 10 is a side cross-sectional view of the quick coupler according to the embodiment. Figure 10 shows a state in which the hydraulic cylinder 6 is extended from the state shown in Figure 9. When the hydraulic cylinder 6 is extended, the movable member 4 rotates in a direction opening relative to the fixed member 2. The distance between the second hook 5 and the first hook 3 becomes greater than in the state shown in Figure 9. The hydraulic cylinder 6 is tilted diagonally with the rod pin 66 side raised from the state shown in Figure 9.

[0037] Figure 11 is a side cross-sectional view of the quick coupler according to the embodiment. Figure 11 shows a state in which the hydraulic cylinder 6 is extended further than the state shown in Figure 10. When the hydraulic cylinder 6 is further extended, the movable member 4 rotates in a direction that further opens relative to the fixed member 2. The distance between the second hook 5 and the first hook 3 becomes greater than in the state shown in Figure 10. The rod pin 66 side of the hydraulic cylinder 6 is lifted up more than in the state shown in Figure 10, and the hydraulic cylinder 6 is tilted at a large angle.

[0038] The hydraulic cylinder 6 configured in this manner maintains its extended state even in an emergency, such as when hydraulic pressure is cut off. The hydraulic cylinder 6 holds the rear end of the slide of the cylinder 61, preventing the locking member 7 from moving to the unlocked position. In this way, the hydraulic cylinder 6 prevents the first pin 111 of the attachment 110 located in the recess 31 of the first hook 3 from falling out.

[0039] FIG. 12 is a perspective view of the locking member. FIG. 13 is a schematic view of the locking member. The locking member 7 prevents the first pin 111 (see FIG. 2) of the attachment 110 from falling off. The locking member 7 locks the first pin 111 in a state where it is engaged with the first hook 3. The locking member 7 is disposed facing the first hook 3. The locking member 7 is rotatably connected to the main body 21 of the fixing member 2 via a lock pin 79. The position where the other end 71b of the main body 71 is separated from the first hook 3 is referred to as the unlocked position. The position where the protrusion 69 of the support portion 67 reaches a position immediately above the lock pin 79 is the unlocked position of the locking member 7. The position where the other end 71b of the main body 71 approaches the first hook 3 is referred to as the locked position. The position where the protrusion 69 of the support portion 67 is separated from a position immediately above the lock pin 79 is the locked position of the locking member 7. The locking member 7 rotates in conjunction with the sliding of the cylinder 61 of the hydraulic cylinder 6, and moves between a locked position and an unlocked position.

[0040] As shown in FIG. 12 , the locking member 7 has a main body 71R located on the right side when viewed from the driver's seat of the hydraulic excavator 100, a main body 71L located on the left side, a connecting portion 77 connecting one end 71Ra of the main body 71R to one end 71La of the main body 71L, and a connecting portion 78 connecting the other end 71Rb of the main body 71R to the other end 71Lb of the main body 71L. The main body 71R and the main body 71L are plate-shaped. The main body 71R and the main body 71L are disposed opposite each other. When it is not necessary to distinguish between the main body 71R and the main body 71L, they will be described as the main body 71. The main body 71 is biased by a first spring 63 and a second spring 64 (see FIG. 8 ) of the hydraulic cylinder 6 so that the other end 71b is positioned in the locked position.

[0041] 13, the main body 71 has a curved surface 72 that faces the first hook 3. The curved surface 72 is convex on the side opposite to the first hook 3.

[0042] The main body 71 has a curved surface 73 that comes into contact with the convex portion 69 of the support portion 67 of the hydraulic cylinder 6. The curved surface 73 is convex on the side opposite to the first hook 3. When the curved surface 73 is pressed by the convex portion 69, the locking member 7 rotates around the lock pin 79 so that the other end 71b approaches the first hook 3 (see FIG. 9).

[0043] A lock pin support hole 74 is formed in one end 71a of the main body 71. The lock pin support hole 74 passes through the connecting portion 77. A lock pin 79 is inserted into the lock pin support hole 74. The lock pin 79 passes through the connecting portion 77.

[0044] The locking member 7 has a curved surface 73 restricted by the protrusion 69 of the support portion 67. The locking member 7 rotates around the locking pin 79 in conjunction with the cylinder pin 68 of the hydraulic cylinder 6 sliding along the elongated hole 24, and moves between a locked position and an unlocked position.

[0045] 5 and 13 show the locking member 7 in the unlocked position. The protrusion 69 presses the curved surface 73 in the vicinity of directly above the locking pin 79. The other end 71b of the main body 71 is spaced apart from the first hook 3. When the locking member 7 is in the unlocked position, the recess 31 of the first hook 3 has a width greater than the diameter of the first pin 111 (see FIG. 2) of the attachment 110. When the locking member 7 is in the unlocked position, the first pin 111 (see FIG. 2) of the attachment 110 can be attached to and detached from the first hook 3.

[0046] 9 and 14 show the locking member 7 in the locked position. FIG. 14 is a schematic diagram showing the locking member. A portion of the curved surface 73 that is shifted to the right of FIG. 13 is pressed by the protrusion 69. The other end 71b of the main body 71 is close to the first hook 3. When the locking member 7 is in the locked position, the recess 31 of the first hook 3 has a width smaller than the diameter of the first pin 111 of the attachment 110. When the locking member 7 is in the locked position, attachment and removal of the first pin 111 of the attachment 110 (see FIG. 2) from the first hook 3 is restricted.

[0047] [Actions and Actions] The following describes the operation and function when replacing the attachment 110. The following describes the case where the attachment 110 attached to the quick coupler 1 is removed and a new attachment 110 is attached. The operator can replace the attachment 110 without getting off the work vehicle.

[0048] Removal of the attachment 110 will be described with reference to FIG. 5. The operator, from the driver's seat, sets the quick coupler 1 to the unlocked position. More specifically, the operator controls the hydraulic pressure supplied from the hydraulic supply pipe 6L to retract the hydraulic cylinder 6. The hydraulic pressure of the hydraulic cylinder 6 acts in the retraction direction of the hydraulic cylinder 6, as indicated by arrow F1. As the hydraulic cylinder 6 retracts, the movable member 4 rotates in a direction to close relative to the fixed member 2. The second pin 112 of the attachment 110 moves away from the second hook 5, and the reaction force disappears. Since the reaction force no longer acts on the cylinder 61, the cylinder 61 of the hydraulic cylinder 6 slides toward the rod pin 66. As the cylinder 61 slides, the cylinder pin 68 slides from the end 24b of the elongated hole 24 opposite the rod pin 66 to the end 24a on the rod pin 66 side. In conjunction with this, the protrusion 69 of the support portion 67 slides in the same direction as the sliding direction of the cylinder 61. The protrusion 69 of the support portion 67 moves to the unlocked position while contacting the curved surface 73 of the locking member 7. The protrusion 69 of the support portion 67 reaches a position immediately above the locking pin 79. The locking member 7 is released from the pressure exerted by the protrusion 69 of the support portion 67. The protrusion 69 of the support portion 67 presses the curved surface 73 of the locking member 7 immediately above the locking pin 79, causing the locking member 7 to rotate and move away from the first hook 3. This causes the recess 31 of the first hook 3 to open widely. In this way, the quick coupler 1 is unlocked.

[0049] The operator operates the work equipment from the driver's seat to remove the attachment 110 from the unlocked quick coupler 1. The operator operates the work equipment of the hydraulic excavator 100 to remove the second pin 112 of the attachment 110 from the second hook 5 and remove the first pin 111 of the attachment 110 from the first hook 3. This removes the attachment 110 from the quick coupler 1.

[0050] The operator operates the work equipment from the driver's seat and attaches the attachment 110 to the quick coupler 1 from which the attachment 110 has been removed. The operator operates the work equipment of the hydraulic excavator 100 and hooks the first pin 111 of the attachment 110 onto the first hook 3, and hooks the second pin 112 of the attachment 110 onto the second hook 5. This attaches the attachment 110 to the quick coupler 1.

[0051] Using Figure 9, we will explain how to lock the attached attachment 110. The operator in the driver's seat places the quick coupler 1 in the locked position. More specifically, the operator controls the hydraulic pressure supplied from the hydraulic supply pipe 6L to extend the hydraulic cylinder 6. The hydraulic pressure of the hydraulic cylinder 6 acts in the extension direction of the hydraulic cylinder 6, as indicated by arrow F2. The hydraulic pressure extends the hydraulic cylinder 6, causing the movable member 4 to rotate in a direction opening relative to the fixed member 2. The second pin 112 of the attachment 110 comes into contact with the second hook 5, generating a reaction force. The reaction force causes the cylinder 61 of the hydraulic cylinder 6 to slide away from the rod pin 66. As the cylinder 61 slides, the cylinder pin 68 slides from the end 24a of the elongated hole 24 on the rod pin 66 side to the end 24b on the opposite side of the rod pin 66. In conjunction with this, the protrusion 69 of the support portion 67 slides in the same direction as the sliding direction of the cylinder 61. The protrusion 69 of the support portion 67 moves to the locked position while contacting the curved surface 73 of the locking member 7. The protrusion 69 of the support portion 67 moves away from directly above the lock pin 79. The protrusion 69 of the support portion 67 restricts the locking member 7 from rotating in the unlocking direction. This restricts the opening of the recess 31 of the first hook 3. In this way, the quick coupler 1 is locked.

[0052] When the second pin 112 of the attachment 110 attached to the quick coupler 1 comes into contact with the second hook 5, a reaction force is generated. The reaction force causes the cylinder 61 of the hydraulic cylinder 6 to slide in the extension direction, operating the locking member 7 from the unlocked position to the locked position and locking the first pin 111 of the attachment 110. As a result, the first pin 111 of the attachment 110 is held in place even when the hydraulic pressure is cut off.

[0053] The hydraulic cylinder 6 has hydraulic pressure maintained by a check valve 6VC, which prevents the first pin 111 of the attachment 110 from falling off the first hook 3 and the second pin 112 of the attachment 110 from falling off the second hook 5.

[0054] The recess 51 of the second hook 5 has an inclined surface 51c that is a return portion. The inclined surface 51c forms an acute angle with respect to a line connecting the center of the link pin 104, which is the rotation center of the movable member 4, and the tip of the inclined surface 51b. As a result, in an emergency such as when hydraulic pressure is cut off, the second pin 112 of the attachment 110 is caught on the inclined surface 51c of the recess 51, preventing the second pin 112 from falling off the quick coupler 1.

[0055] FIG. 15 is a side cross-sectional view of a quick coupler according to an embodiment. The quick coupler 1 may assume such a posture depending on the posture of the work implement of the hydraulic excavator 100. A case will be described in which the quick coupler 1 is in the posture shown in FIG. 15 and hydraulic pressure is lost while the work implement of the hydraulic excavator 100 is being moved. Due to inertia of the attachment 110 or the like, the first pin 111 of the attachment 110 and the first hook 3, and the second pin 112 of the attachment 110 and the second hook 5 may not come into contact. In this case, the weight of the second hook 5 and the weight of the rod 62 of the hydraulic cylinder 6 are supported by the first spring 63 and the second spring 64, preventing the second hook 5 from falling due to gravity.

[0056] [effect] In this embodiment, when the second pin 112 of the attachment 110 attached to the quick coupler 1 comes into contact with the second hook 5, a reaction force is generated. The reaction force causes the cylinder 61 of the hydraulic cylinder 6 to slide in the extension direction, causing the locking member 7 to move from the unlocked position to the locked position, thereby locking the first pin 111 of the attachment 110. This holds the first pin 111 of the attachment 110 even when the hydraulic power is cut off.

[0057] In this embodiment, the recess 51 of the second hook 5 has a curved surface 51a, an inclined surface 51b, and an inclined surface 51c. The inclined surface 51c forms an acute angle with respect to a line connecting the center of the link pin 104, which is the rotation center of the movable member 4, and the tip of the inclined surface 51b. This allows the second pin 112 of the attachment 110 to be caught on the inclined surface 51c of the recess 51 in an emergency, such as when hydraulic pressure is cut off, preventing the second pin 112 from falling off the quick coupler 1.

[0058] In this embodiment, the check valve 6VC normally maintains the hydraulic pressure of the hydraulic cylinder 6. This prevents the first pin 111 of the attachment 110 from falling off the first hook 3 and the second pin 112 of the attachment 110 from falling off the second hook 5.

[0059] In the embodiment, the quick coupler 1 may assume a position as shown in Fig. 15. If hydraulic pressure is lost while the work implement of the hydraulic excavator 100 is being operated, the first pin 111 of the attachment 110 may not come into contact with the first hook 3, and the second pin 112 of the attachment 110 may not come into contact with the second hook 5, due to inertia of the attachment 110 or the like. In this case, the weight of the second hook 5 and the weight of the rod 62 of the hydraulic cylinder 6 can be supported by the first spring 63 and the second spring 64. According to the embodiment, it is possible to prevent the second hook 5 from falling due to gravity.

[0060] In this way, according to the embodiment, it is possible to prevent the attachment 110 from falling off in an emergency such as when hydraulic pressure is cut off. According to the embodiment, it is possible to provide a quick coupler 1 that is highly safe and easy to handle.

[0061] The embodiment eliminates the need to manually attach and detach a safety pin to secure the quick coupler 1 to the attachment 110. According to the embodiment, the operator does not need to get out of the driver's seat and work near the work vehicle to attach or detach the quick coupler 1. According to the embodiment, the operator can replace the attachment 110 without getting out of the work vehicle. According to the embodiment, the effort required to replace the attachment 110 is reduced, and operator safety can be maintained at a higher level.

[0062] In the embodiment, the distance between the second hook 5 and the first hook 3 changes as the movable member 4 rotates relative to the fixed member 2. In the embodiment, the distance between the second hook 5 and the first hook 3 can be in the range of, for example, 180 mm or more and 300 mm or less. The embodiment can be applied to various attachments.

[0063] In this embodiment, the movable member 4 is provided rotatably relative to the fixed member 2. In this embodiment, the overall size of the quick coupler 1 can be reduced when the distance between the second hook 5 and the first hook 3 is minimized. According to this embodiment, the quick coupler 1 does not interfere with the work of the work vehicle to which it is attached.

[0064] In the embodiment, the curved surface 69a of the convex portion 69 moves while pressing the curved surface 73 of the locking member 7, thereby moving between the locked position and the unlocked position. In the embodiment, the curved surface 69a of the convex portion 69 can be kept in contact with the curved surface 73 of the locking member 7 regardless of the attitude of the hydraulic cylinder 6.

[0065] In the embodiment, the first hook 3 has a tapered portion that contacts the first pin 111 hooked on the first hook 3. According to the embodiment, rattle of the first pin 111 of the attachment 110 in the recess 31 of the first hook 3 can be suppressed.

[0066] In the embodiment, the second hook 5 has a tapered portion that contacts the second pin 112 hooked on the second hook 5. According to the embodiment, rattle of the second pin 112 of the attachment 110 at the recess 51 of the second hook 5 can be suppressed.

[0067] Although the embodiments have been described above, the embodiments are not limited to the above content. Furthermore, the above-described components include those that can be easily imagined by a person skilled in the art, those that are substantially the same, and those that are within the so-called equivalent range. Furthermore, the above-described components can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the components can be made without departing from the spirit of the embodiments. [Explanation of symbols]

[0068] 1...quick coupler, 2...fixing member, 3...first hook, 3a...tip portion, 4...movable member, 5...second hook, 5a...tip portion, 6...hydraulic cylinder (spring-loaded cylinder), 6a...one end portion, 6b...other end portion, 6c...wall portion, 6L...hydraulic pressure supply pipe, 6VB...flow path, 6VC...check valve, 7...locking member, 21...main body portion, 22...arm pin support hole, 23...link pin support hole, 24...long hole, 25...lock pin support hole, 28...connection portion, 31...recess, 31b...inclined surface (taper), 41...main body portion, 42...rod pin support hole, 43...link pin support hole, 48...wall portion, 51...recess, 51a...curved surface, 51b ...inclined surface (taper), 51c...inclined surface (return portion), 61...cylinder, 62...rod, 63...first spring, 64...second spring, 65...rod pin support hole, 66...rod pin, 67...support portion, 68...cylinder pin, 69...convex portion, 69a...curved surface, 71...main body portion, 71a...one end portion, 71b...other end portion, 72...curved surface, 73...curved surface, 74...lock pin support hole, 77...connection portion, 78...connection portion, 79...lock pin, 100...hydraulic excavator, 101...arm, 102...link member, 103...arm pin, 104...link pin, 110...attachment, 111...first pin, 112...second pin.

Claims

1. a fixing member having a first hook with which a first pin of an attachment of the work vehicle can be engaged; a movable member having a second hook with which the second pin of the attachment can be engaged, the movable member being rotatably provided on the fixed member; a hydraulic cylinder having one axial end fixed to the fixed member and the other axial end fixed to the movable member, the hydraulic cylinder having a spring for biasing the hydraulic cylinder in an extension direction; a locking member disposed on the fixing member and configured to lock the first pin in a state where the first hook is engaged with the first pin; Equipped with the second hook has a barb at its tip, The spring has an extension force capable of supporting the weight of the second hook and the weight of the hydraulic cylinder. Quick coupler.

2. The quick coupler according to claim 1 , wherein the barb forms an acute angle with respect to a line connecting the rotation center of the movable member and a base end of the barb.

3. The quick coupler according to claim 1 or 2, wherein a portion of the first hook that contacts the first pin is tapered.

4. The quick coupler according to claim 1 , wherein a portion of the second hook that contacts the second pin is tapered.

5. a slot formed in the fixing member; a cylinder pin disposed in the cylinder of the hydraulic cylinder and slidably engaged with the elongated hole; Equipped with 5. The quick coupler according to claim 1, wherein the locking member is rotatably disposed on the fixed member and moves between a locked position and an unlocked position in conjunction with the cylinder pin sliding along the elongated hole.

6. a protrusion disposed on the cylinder of the hydraulic cylinder and sliding in conjunction with the cylinder pin; Equipped with the protrusion has a curved surface that comes into contact with the curved surface of the locking member, The quick coupler according to claim 5, wherein the curved surface of the convex portion moves while pressing against the curved surface of the locking member, thereby moving between the locked position and the unlocked position.

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