JPH0687448U - Quick coupler - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] To make it possible to visually check the connection and disconnection state of the hitch and hook from the driver's seat very easily. A pair of display member mounting rods 104, 106 is rotatably supported on the back surface of the hitch 4 and is arranged so as to extend vertically upward. Lock pin 90,
Between each of the reference numerals 92 and their corresponding display member mounting rods, the horizontal direction movement of each lock pin between the non-engaging position and the engaging position with respect to the pair of hooks is carried out. A movement direction conversion means for converting into movement is provided. An indicator member 104 is provided on the upper end of each indicator member mounting rod to indicate which of the two positions each lock pin is in with respect to each hook.
b and 106b are provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a quick coupler for removably attaching a working device to a front end portion of an earthmoving vehicle, and more particularly to a quick coupler having a lock pin position display device provided on a hitch.

[0002]

[Prior art]

 As this type of conventional quick coupler, for example, the one disclosed in Japanese Utility Model Publication No. 4-5569 can be mentioned. The quick coupler disclosed in this publication is fixed to the front end of the earthmoving vehicle, for example, the front end of the lift arm and the tilt link, and the back of a work device such as a bucket or blade with a lateral gap. It consists of a pair of hooks. The hitch horizontally extends between two positions, a disengagement position located laterally inward of each of the hooks and an engagement position protruding laterally outward from the disengagement position. A pair of movably arranged lock pins and a fluid pressure cylinder mechanism for simultaneously moving the lock pins are provided. A lever member mounted so as to be rotatable is connected to each of the lock pins. The fluid pressure cylinder mechanism is configured to act on each of the lock pins via each of the lever members. Therefore, by operating the fluid pressure cylinder mechanism, each of the lock pins can be selectively positioned at either the non-engagement position or the engagement position with respect to each of the hooks. That is, the operator can freely control the attachment / detachment of the work device from the driver's seat.

The fluid pressure cylinder mechanism, each lever member, each lock pin, and the like are housed in a box-shaped lower connecting means provided in a hitch so as to extend in the lateral direction in order to protect the hydraulic cylinder mechanism from adhesion of earth and sand and external load. It is configured so that it cannot be seen from the outside. For this reason, a position display device is provided for confirming whether each of the lock pins is in the disengaged position or the engaged position with respect to each of the hooks. The position display device includes a pair of pointing members that rotate integrally with each of the lever members. Each indicating member is arranged outside the back side of the lower connecting means. Since each indicator moves in association with each lock pin, whether each lock pin is in the disengaged position or the engaged position depending on the angular position of each indicator, that is, the decoupling of the hitch and the hook. And the connection status can be confirmed.

[0004]

[Problems to be solved by the device]

 Since the respective indicating members are arranged outside the rear side of the lower connecting means, their positions can be confirmed from the driver's seat. However, the mounting position of each indicating member is below the quick coupler, that is, below the hitch, and is considerably lower than the driver's seat. As a result, the members located between the driver's seat and the quick coupler, such as the lift arm cross member and tilt cylinder, obstruct the forward field of view from the driver's seat. There is a problem that the position of the member is difficult to see. Extending each indicator member upward or relocating it upward enough to eliminate the above-mentioned problems is caused by its own operating mode, its relation to the surrounding structure, etc. It is practically impossible.

An object of the present invention is to provide an improved quick coupler capable of visually confirming the disconnection and connection state of the hitch and hook from the driver's seat.

[0006]

[Means for Solving the Problems]

 In order to achieve the above object, according to the present invention, a hitch mounted on the front end of an earthmoving vehicle and a pair of hooks laterally fixed to the rear surface of the working device, the hitch comprising: , A horizontally movably arranged position between each of the hooks, that is, a disengagement position located inward of the hooks in the lateral direction and an engagement position protruding laterally outward from the disengagement position. A quick coupler having a pair of lock pins provided, a fluid pressure cylinder mechanism for simultaneously moving each of the lock pins, and a position display device for displaying the two positions of each of the lock pins. The position display device is rotatably supported on the back surface of the hitch at a distance in the lateral direction, and is attached to each of the lock pins so as to extend vertically upward. Rod and the lock pin Horizontal movement between the two positions of each of the lock pins, which is provided between each of the corresponding display member mounting rods and the corresponding display member mounting rods. And a moving direction converting means for converting each of the lock pins to the upper end portion of each of the display member mounting rods by rotating between the two positions together with each of the display member mounting rods. There is provided a quick coupler characterized by being provided with a display member for displaying which one of the two positions is present for each hook.

[0007]

[Action]

 When the hydraulic cylinder mechanism is not supplied with pressure oil, each of the lock pins is located at a disengaged position located laterally inward of each of the hooks. In this non-engaged state, each of the display members provided on the upper end portion of each display member mounting rod is positioned at one rotational position (one angular position). That is, one rotational position of each of the indicating members indicates that each of the locking pins is in a disengaged position with respect to the hook, and thus the hitch and hook are in a disengaged state.

When pressure fluid is supplied to the fluid pressure cylinder mechanism by operating means well known to those skilled in the art, each of the lock pins moves in the horizontal direction at the same time from the disengaged position with respect to the corresponding hook. It is positioned at an engaging position that projects laterally outward. This horizontal movement (linear movement) is converted into the rotation direction movement (rotational movement) of the corresponding display member mounting rod via the movement direction conversion means, and each of the display members has a corresponding display member. It rotates from the one rotational direction position together with the mounting rod and is positioned at another rotational direction position (another angular position). The other rotational position of each of the indicating members indicates that each of the locking pins is in the engaged position with respect to the hook, and thus the hitch and hook are in a coupled condition.

Since each display member mounting rod is arranged on the back surface of the hitch so as to extend vertically upward, the display member provided at the upper end of each is positioned above the hitch. As a result of each display member being positioned at a position where it can be easily seen from the driver's seat, the operator can easily visually check from the driver's seat which of the two positions each of the display members is in. In other words, the operator can easily visually confirm the connection and disconnection state of the hitch and the hook while sitting from the driver's seat.

The forward view from the driver's seat varies depending on the type of earthmoving vehicle. In this consideration, as described above, each display member mounting rod is arranged so as to extend vertically upward on the back surface of the hitch. It is extremely easy to properly select the length of each display member mounting rod. Therefore, it is easy to set the vertical position of each display member according to the front field of view, which differs depending on the model. Extending the length of each display member mounting rod is very useful in practical use because the above configuration has a very wide range of application, since there is no problem of interference with peripheral members.

Each of the display members is provided so as to horizontally project outward in the radial direction from the upper end of the corresponding display member mounting rod. The tip of each indicator member is directed in the straight ahead direction of the earthmoving vehicle when each of the lock pins is in the disengaged position, and in the lateral direction orthogonal to the straight ahead direction when each of the lock pins is in the engaged position. The interlocking relationship between each of the lock pins and the corresponding display member mounting rods is defined through the movement direction converting means so as to face in the direction away from each other. Therefore, while the operator is sitting from the driver's seat, whether the position of each tip of the display member is directed in the straight traveling direction of the earthmoving vehicle or in the lateral direction orthogonal to the straight traveling direction and away from each other. Since it is possible to visually determine, it is possible to easily and surely determine whether the hitch and the hook are in the non-connected state or the connected state.

The hitch is provided with a box-shaped lower connecting means extending in the lateral direction. The fluid pressure cylinder mechanism, each of the lock pins, the lower portion of each of the display member mounting rods, and the moving direction changing means are housed in the lower connecting means. The upper portion of each of the display member mounting rods is configured to project relatively rotatably upward through a through hole formed at an upper position of the lower connecting means. That is, at the upper position of the lower connecting means, only through holes are formed for allowing the respective display member mounting rods to relatively freely pass therethrough, and no extra openings are formed. As a result, intrusion of earth and sand or the like into the lower connecting means is reliably prevented, so that the storage member such as the fluid pressure cylinder mechanism can be reliably protected.

[0013]

【Example】

 Hereinafter, an embodiment of a quick coupler constructed according to the present invention will be described in detail with reference to the accompanying drawings. Referring to FIGS. 1 and 2, a quick coupler, generally designated by reference numeral 2, has a hitch 4 mounted on a front end portion of an earthworking vehicle (not shown) and a lateral space on a rear surface of a working device (not shown). And a pair of hooks 6 (one of which is shown in FIG. 1 and the other is shown in FIG. 5) which are fixed. In this specification, the “lateral direction” means the left-right direction in FIG. 1 and the front-back direction in FIG. 2, and the “straight direction of earthmoving vehicle” means the direction from the front surface to the back surface in FIG. The directions are from left to right. First, the configurations of the hitch 4 and the hook 6 will be described.

Referring to FIGS. 5 and 6, the hitch 4 includes a pair of center plates 8 and 10 arranged laterally at a center in the lateral direction, and a lateral outside of the center plates 8 and 10. A pair of intermediate plates 12 and 14 which are respectively arranged at equal intervals, and a pair of outer plates 16 and 18 which are arranged at the same intervals laterally outward of the intermediate plates 12 and 14, respectively. ing. Each plate is connected by an upper connecting means 20 and a lower connecting means 22 arranged so as to extend laterally. The upper connecting means 20 includes a tube 24 and two round bar members 26 and 28. These are located coaxially. Both ends of the tube 24 are fixed to the upper end portions of the intermediate plates 12 and 14, respectively, and the intermediate portion penetrates the upper end portions of the central plates 8 and 10 and is fixed at the penetrating portions thereof. Both ends of the round bar member 26 are fixed to the outer plate 16 and the intermediate plate 12, respectively, and both ends of the round bar member 28 are fixed to the outer plate 18 and the intermediate plate 14, respectively. The central plates 8 and 10 are further connected by a reinforcing plate 30 (see FIG. 9). Further, the central plate 8 and the intermediate plate 12 and the central plate 10 and the intermediate plate 14 are connected by channel members 32 and 34, respectively (see FIG. 8). The intermediate plate 12 and the outer plate 16 are connected to each other by the reinforcing plates 36 and 38, and the intermediate plate 14 and the outer plate 18 are connected to each other (see FIG. 7).

The lower connecting means 22 is a channel member 40 connecting the central plates 8 and 10 (see FIG. 5), a channel member connecting the central plate 8 and the intermediate plate 12, and a channel member connecting the central plate 10 and the intermediate plate 14, respectively. 42 and 44 (see FIGS. 8 and 9). The cross-sectional shapes of the channel members 40, 42 and 44 are substantially the same, with their open sides facing the back of the hitch 4 (left of FIGS. 6-9). The open side of the channel member 40 is closed by fixing a reinforcing plate 46 (see FIG. 9). A plate 50 having an opening 48 formed in the center is fixed to the open side of the channel member 42 (see FIG. 8), and a plate 54 having an opening 52 formed in the center is fixed to the open side of the channel member 44. . The openings 48 and 52 are detachably covered by cover plates 56 and 58, respectively (see FIGS. 1 and 2). The channel members 40, 42 and 44 and the reinforcing plate 46 and the cover plates 56 and 58 respectively covering the open sides of the channel members 40, 42 and 44 constitute a box-shaped lower connecting means 22 extending in the lateral direction. In relation to the lower connecting means 22, openings 58 and 60 are formed in the central plates 8 and 10, respectively. As a result, one storage space continuous in the lateral direction is formed in the box-shaped lower connecting means 22.

Boss portions 62 and 64 are provided in portions of the intermediate plates 12 and 14 facing the storage space, respectively. Through holes 66 and 68 are formed in the boss portions 62 and 64, respectively. Bosses 70 and 72 are provided on the sides of the outer plates 16 and 18 facing the intermediate plates 12 and 14, respectively. Through holes 74 and 76 are formed in the boss portions 70 and 72, respectively. These through holes 66, 68, 74 and 76 are located on the same axis and have substantially the same inner diameter. Hooks 6 are respectively positioned between the intermediate plate 12 and the outer plate 16 and between the intermediate plate 14 and the outer plate 18 (only the other of the hooks 6 is shown in FIG. 5). Each hook 6 is provided with a hook 6a at its upper end and a through hole 6b at its lower end. When the hook portion 6a of each hook 6 is engaged with the round bar members 26 and 28, one of the through holes 6b is positioned on the same axis as the through holes 66 and 74, and the other of the through holes 6b is inserted into the through hole 6b. It is co-axial with holes 68 and 76.

Boss portions 78 each having a through hole are provided on the same axis line at intermediate positions in the vertical direction of the center plates 8 and 10. A boss portion 80 having a through hole is provided on each of the lower end positions of the intermediate plate 12 and the outer plate 16 and the lower end positions of the intermediate plate 14 and the outer plate 18 on the same axis. The boss portion 78 is pivotally connected to a tilt link of an earthmoving vehicle (not shown) as an example, and the boss portion 80 is pivotally connected to a lift arm (not shown) as an example.

The configurations of the hitch 4 and the hook 6 described above are basically the same as the configurations disclosed in the above publication. Next, a description will be given of the components improved according to the present invention. Referring to FIGS. 5 and 8, an upper support 82 is fixed to the lower surface of the channel member 32. The upper support 82 is composed of a rectangular plate, and a through hole 82a is formed in its horizontal end portion. A through hole 42 a is formed in the horizontal upper portion of the channel member 42 located below the upper support 82. One end of a lower support 84 that horizontally projects into the storage space is fixed to the intermediate plate 12, and a through hole 84a is formed at the other end. Each of these through holes 82a, 42a and 84a is positioned on a common vertical axis. Similarly, an upper support 86 is fixed to the lower surface of the channel member 34. The upper support 86 is composed of a rectangular plate, and a through hole 86a is formed at the horizontal end thereof. A through hole 44a is formed in the horizontal upper portion of the channel member 44 located below the upper support 86. One end of a lower support 88 that horizontally projects into the storage space is fixed to the intermediate plate 14, and a through hole 88a is formed at the other end. Each of these through holes 86a, 44a and 88a is positioned on a common vertical axis.

Referring next to FIGS. 1 to 4, the hitch 4 includes a pair of lock pins 90 and 92 and a fluid pressure cylinder mechanism 94. The lock pins 90 and 92 have a non-engagement position (a position shown by a solid line in FIG. 1) located inward of the corresponding hook 6 (only one of them is shown in FIG. 1) and a non-engagement position. It is provided so as to be movable in the horizontal direction between an engaging position (a position indicated by a chain double-dashed line in FIG. 1) protruding laterally outward from the engaging position. This movement is simultaneously performed by the fluid pressure cylinder mechanism 94. The fluid pressure cylinder mechanism 94 is attached to the channel member 42 by a bolt 98 via a mounting bracket 96 fixed to the fluid pressure cylinder mechanism 94. Two movable pistons (not shown) are housed in the fluid pressure cylinder mechanism 94. The piston rod 100 of one movable piston is connected to one end of the lock pin 90, and the piston rod 102 of the other movable piston is locked. It is connected to one end of 92. The other end of the lock pin 90 is fitted in the through hole 66 of the boss portion 62 of the intermediate plate 12, and the other end of the lock pin 92 is fitted in the through hole 68 of the boss portion 64 of the intermediate plate 14.

The hitch 4 further includes a position display device for displaying the two positions of the lock pins 90 and 92. This position display device has a pair of display member mounting rods 104 and 106 and a rotational direction between the two positions of the display member mounting rods 104 and 106, which correspond to horizontal movement between the lock pins 90 and 92 between the two positions, respectively. And a movement direction conversion means for converting into movement. The display member mounting rods 104 and 106 are arranged on the rear surface of the hitch 4 at intervals in the lateral direction so as to extend vertically upward in correspondence with the lock pins 90 and 92, respectively. The display member mounting rod 104 is rotatably supported in the through holes 82a, 42a and 84a (see FIG. 5) of the upper support 82, the channel member 42 and the lower support 84, respectively. The display member mounting rod 104 has a large-diameter flange portion 104a formed at an upper position of the upper support 82 in order to prevent it from coming out downward, and a lower position of the upper support 82 in order to prevent coming out upward. The beta pin 108 is inserted into the through hole formed in the. The display member mounting rod 106 is rotatably supported in the through holes 86a, 44a and 88a (see FIG. 5) of the upper support 86, the channel member 44 and the lower support 88, respectively. The display member mounting rod 106 has a large-diameter flange portion 106a formed at an upper position of the upper support 86 in order to prevent downward pull-out, and a lower position of the upper support 82 in order to prevent upward pull-off. The beta pin 110 is inserted into the through hole formed in the.

A display member 104b is provided on the upper end of the display member mounting rod 104, and a display member 106b is provided on the upper end of the display member mounting rod 106 so as to project outward in the radial direction in a horizontal plane. There is. The display members 104b and 106b are rotationally moved between the two positions (between the two angular positions) together with the corresponding display member mounting rods 104 and 106, so that the lock pins 90 and 92 are moved relative to the hooks 6 at the two positions. It is for displaying in which of the above.

A U-shaped bracket 112 is attached to the lock pin 90, and a U-shaped bracket 114 is attached to the lock pin 92. A boss member 116 is supported on the bracket 112, and a boss member 118 is supported on the bracket 114 so as to be rotatable about a vertical axis. A connecting rod 120 is attached to the boss member 116, and a connecting rod 122 is attached to the boss member 118 so as to project outward in the radial direction. Through holes are formed near the lower ends of the display member mounting rods 104 and 106, respectively. The tip of the connecting rod 120 is slidably inserted into the through hole of the display member mounting rod 104, and the tip of the connecting rod 122 is slidably inserted into the through hole of the display member mounting rod 106. The moving direction converting means is composed of boss members 116 and 118, connecting rods 120 and 122, through holes formed in the display member mounting rods 104 and 106, and the like.

When the hydraulic oil is not supplied to the fluid pressure cylinder mechanism 104, the lock pins 90 and 92 are positioned at the non-engaging positions with respect to the hooks 6. In this disengaged state, the tips of the display members 104b and 106b are positioned so as to face forward from the back surface of the hitch 4, as shown by the solid line in FIGS. This direction corresponds to the forward direction of earthmoving vehicles. When the hydraulic oil is supplied to the fluid pressure cylinder mechanism 104, the lock pins 90 and 92 simultaneously move horizontally outward in the horizontal direction, and the lock pins 90 and 92 move laterally outward from the disengaged position with respect to the corresponding hook 6. It is located at the engaging position that protrudes to the left (the position indicated by the two-dot chain line in FIG. 1). The lock pin 90 projects to the outside of the intermediate plate 12, penetrates the through hole 6b of the one hook 6, and the tip end thereof is fitted and supported by the through hole 74 of the boss portion 70. The lock pin 92 projects to the outside of the intermediate plate 14 and penetrates the through hole 6b (see FIG. 5) of the other hook 6, and its tip is fitted and supported by the through hole 76 of the boss 72. . Each hook 6 is connected to the hitch 4. The horizontal movement of the lock pin 90 is converted into the rotational movement of the display member mounting rod 104 via the boss member 116, the connecting rod 120 and the like. Further, the horizontal movement of the lock pin 92 is converted into the rotational movement of the display member mounting rod 106 via the boss member 118, the connecting rod 122 and the like. As a result, the tips of the display members 104b and 106b are positioned so as to face outward in the lateral direction, as indicated by the chain double-dashed line in FIG. That is, they are positioned so that they are laterally orthogonal to the direction in which the earthmoving vehicle travels straight and are spaced apart from each other.

The hitch 4 is provided with the box-shaped lower connecting means 22 extending in the lateral direction as described above. The fluid pressure cylinder mechanism 94, the lock pins 90 and 92, the respective lower parts of the display member mounting rods 104 and 106, and the above-mentioned moving direction changing means are housed in the lower connecting means 22, respectively. The upper portions of the display member mounting rods 104 and 106 are relatively rotatable through upper positions of the lower connecting means 22, specifically, through holes 42a and 44a (see FIG. 5) formed in the channel members 42 and 44. It is configured to project upward.

The present invention has been described above in detail based on the embodiments. However, the present invention is not limited to the above embodiments, and various modifications or modifications can be made within the scope of the present invention. It is a thing. For example, the moving direction changing means uses the boss members 116 and 118 as pin members, fixes one ends of the connecting rods 120 and 122 to the corresponding display member mounting rods 104 and 106, and forks one end of the connecting rods 120 and 122, respectively. The shape may be such that they are engaged with the corresponding pin members.

[0026]

[Effect of device]

 According to the quick coupler constructed according to the present invention, the following effects are achieved. (1) Since the display member mounting rods are arranged so as to extend vertically upward on the back surface of the hitch, the display members provided on the respective upper end portions are positioned above the hitch. As a result of each display member being positioned at a position that is easily visible from the driver's seat, the operator can very easily visually confirm from the driver's seat which of the two positions each of the display members is in. That is, the operator can easily visually check the connection and disconnection state of the hitch and the hook while sitting from the driver's seat. (2) The forward visibility from the driver's seat varies depending on the type of earthwork vehicle. In this invention, as described above, each display member mounting rod is arranged on the rear surface of the hitch so as to extend vertically upward. It is extremely easy to properly select the length of each display member mounting rod. Therefore, it is easy to set the vertical position of each display member according to the front field of view which differs depending on the model. By extending the length of each display member mounting rod, there is no problem of interference with peripheral members, so that the above-mentioned configuration has a wide range of practical applications and is useful. (3) Each of the display members is provided so as to horizontally project radially outward from the upper end of the corresponding display member mounting rod. The tip of each indicator member is directed in the straight ahead direction of the earthmoving vehicle when each of the lock pins is in the disengaged position, and in the lateral direction orthogonal to the straight ahead direction when each of the lock pins is in the engaged position. The interlocking relationship between each of the lock pins and the corresponding display member mounting rods is defined through the movement direction conversion means so as to face in the direction away from each other. Therefore, when the operator sits down from the driver's seat, the position of the tip of each display member is directed in the straight ahead direction of the earthmoving vehicle or in the lateral direction orthogonal to the straight ahead direction and away from each other. Since it is possible to visually determine whether or not the hitch and the hook are in a non-connected state or a connected state, it is possible to easily and surely determine. (4) The hitch has a box-shaped lower connecting means extending in the lateral direction. The fluid pressure cylinder mechanism, each of the lock pins, the lower portion of each of the display member mounting rods, and the moving direction changing means are housed in the lower connecting means. The upper portion of each of the display member mounting rods is configured to project upward rotatably relative to each other through through holes formed in the upper position of the lower connecting means. That is, a through hole is formed in the upper position of the lower connecting means so that each of the display member mounting rods penetrates relatively rotatably, and no extra opening is formed. As a result, intrusion of earth and sand or the like into the lower connecting means is reliably prevented, so that the storage member such as the fluid pressure cylinder mechanism can be reliably protected.

[Brief description of drawings]

FIG. 1 is a rear view of the essential parts of an embodiment of a quick coupler constructed according to the present invention. For convenience of explanation, only a main part relating to the present invention is shown by a solid line (the same applies to FIGS. 2 to 4).

FIG. 2 is a view of FIG. 1 seen from the right side and is a partially cutaway view.

FIG. 3 is a sectional view taken along the line AA of FIG.

FIG. 4 is a sectional view taken along the line BB of FIG.

5 is a view of the hitch included in the quick coupler shown in FIG. 1 as seen from the back side, and a view showing a part of the hitch broken away.

FIG. 6 is a diagram of FIG. 5 viewed from the right side.

7 is a cross-sectional view taken along the line CC of FIG.

8 is a cross-sectional view taken along the line DD of FIG.

9 is a sectional view taken along the line EE of FIG.

[Explanation of symbols]

 2 Quick Coupler 4 Hitch 6 Hook 22 Lower Connecting Means 90 and 92 Lock Pin 94 Fluid Cylinder Mechanism 104 and 106 Display Member Attachment Rods 104b and 106b Display Member

Claims (4)

[Scope of utility model registration request] 1. A hitch mounted on the front end of an earthmoving vehicle, and a pair of hooks fixed laterally to the rear surface of the work device at a distance from each other, the hitch corresponding to each of the hooks. A pair of lock pins arranged movably in the horizontal direction between two positions, that is, a non-engaging position located inward in the lateral direction and an engaging position projecting laterally outward from the non-engaging position, In a quick coupler including a fluid pressure cylinder mechanism for simultaneously moving each of the lock pins and a position display device for displaying the two positions of each of the lock pins, the position display device includes a rear surface of the hitch. A pair of display member mounting rods, which are rotatably supported at a distance in the lateral direction and are arranged corresponding to the respective lock pins so as to extend upward in the vertical direction; Corresponding display section Moving direction converting means provided between the mounting rods and converting horizontal movement between the two positions of each of the lock pins into rotational movement between the corresponding two positions of the display member mounting rod, respectively. At the upper end of each of the display member mounting rods, each of the locking pins is moved to one of the two positions with respect to each of the hooks by rotationally moving between the two positions together with each of the display member mounting rods. A quick coupler characterized by being provided with a display member for indicating whether there is any. 2. Each of the display members is provided so as to horizontally project outward in the radial direction from the upper end of the corresponding display member mounting rod, and the tip of each of the display members is provided with each of the lock pins. When the lock pins are in the non-engagement position, the lock pins are oriented in the straight-ahead direction, and when the lock pins are in the engagement position, the lock pins are oriented in a lateral direction orthogonal to the straight-ahead direction and away from each other. 2. The quick coupler according to claim 1, wherein the interlocking relationship between each of the lock pins and the corresponding display member mounting rod is defined through the movement direction converting means. 3. The hitch includes a laterally extending box-shaped lower connecting means, the fluid pressure cylinder mechanism, each of the lock pins, and a lower portion of each of the display member mounting rods.
The moving direction changing means is housed in the lower connecting means, and an upper portion of each of the display member mounting rods is relatively rotatably upward through a through hole formed in an upper position of the lower connecting means. The quick coupler according to claim 1, wherein the quick coupler is configured to project. 4. The moving direction converting means is provided on each of the lock pins so as to be rotatable about a vertical axis, and each of the boss members is provided so as to project outward in the radial direction. A connecting rod and a through hole formed in the vicinity of the lower end of each of the display member mounting rods, and the tip of each of the connecting rods slides into the through hole of the corresponding display member mounting rod. The quick coupler according to claim 1, wherein the quick coupler is inserted freely.