JP2012025285A - Dump truck - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dump truck in which a member other than a hinge pin can support at least a front-direction inertia force among inertia forces acting on a cargo bed.SOLUTION: The dump truck includes: a frame (2); the hinge pins (4) arranged on a rear part of the frame (2); and the cargo bed (1) attached freely turnably to the frame (2) via the hinge pins (4), wherein a front stopper structure (Sf) for supporting the front-direction inertia force acting on the cargo bed (1) by abutting against a front part (12) of the cargo bed (1) seated on the frame (2) is disposed on the frame (2), the front stopper structure is configured in such a way that a front abutting plate which abuts against the front part of the cargo bed is turned by a four-bar linkage (10).

Description

  The present invention relates to a dump truck that transports an object to be transported such as earth and sand, and more particularly to a structure for reducing a load acting on a hinge pin that connects a cargo bed and a frame.

  As shown in FIG. 18, the large dump truck for construction machines includes a frame 2 as a main body and a loading platform 1 for loading earth and sand. The frame 2 and the loading platform 1 include a hoist cylinder 3 and a hinge pin 4. It is connected with. When the hoist cylinder 3 is expanded and contracted, the loading platform 1 rotates with respect to the frame 2 in the vertical direction with the hinge pin 4 as a fulcrum.

  When the dump truck is started and stopped, an inertial force in a direction opposite to the direction of the acceleration acts on the loading platform due to the longitudinal acceleration generated at that time. Further, since the contact surface between the frame and the loading platform is inclined forward and inclined, the loading platform is always pulled forward by gravity. Further, when the dump truck turns, a centrifugal force (inertial force) acts on the loading platform.

  In the conventional dump truck, most of the inertial force acting on the loading platform is supported by a hinge pin. Therefore, an excessive load is applied to the hinge pin, and the long-term use of the dump truck causes the frame side connecting hole into which the hinge pin is inserted and the surrounding members (for example, the place where the hinge pin is attached on the bottom surface of the loading platform) There may be a problem with the surrounding area. In order to prevent such a problem, it is important to reduce the load applied to the hinge pin.

  By the way, the dump truck has a longer running time than the time to take down the earth and sand loaded on the loading platform, and the inertial force acting on the dump truck during this running is It is generally known that the forward direction at the time of deceleration is the largest than the backward direction at the time of acceleration. Furthermore, in the case of a dump truck, as described above, the frame is shaped so as to be inclined downward from the rear to the front, so that the hinge pin is always loaded in the forward direction due to the gravity of the loading platform. is there. Therefore, the load acting on the hinge pin is the largest in the forward direction, and in order to reduce the load acting on the hinge pin, how to support the inertial force acting in the forward direction acting on the loading platform at a part other than the hinge pin. It can be said that it is important.

  Here, a pad made of an elastic material such as rubber (see reference numeral 6 in FIG. 18) is usually attached to the bottom surface of the loading platform. This pad is provided to prevent the loading platform from vibrating during travel and to absorb the shock to the frame when loading earth and sand on the loading platform. When this occurs, a frictional force is generated between the pad and the frame. By this frictional force, it is possible to support the inertial force in a forward direction acting on the loading platform to a small extent.

  In addition, two guides (see reference numeral 5a in FIG. 18) protruding downward are provided on the left and right when viewed from the front side of the dump truck. Also, the frame is provided with two guide pads (see reference numeral 5b in FIG. 18) that abut against each of the two guides. With this configuration, when the loading platform is in a lying posture in which it is seated on the frame, the guide faces the guide pad. And, for example, during turning, when the loading platform moves in the left-right direction with respect to the frame (the direction of rotation about the vertical direction), the loading platform moves in the left-right direction by contacting the guide abutment. To be restricted. Therefore, since the centrifugal force acting on the loading platform can be supported to some extent by the configuration of the guide and the guide pad, the load in the left-right direction applied to the hinge pin can be reduced.

  Furthermore, a loading platform seating device as shown in Patent Document 1 has been devised so far. This receives the front end of the loading platform with a seating device inclined in the left-right direction of the vehicle body and suppresses the movement of the loading platform in the left-right direction with respect to the frame. Also by this patent document 1, since the centrifugal force which acts on a loading platform can be supported, the load of the left-right direction applied to a hinge pin can be reduced.

JP 2007-176251 A

  However, in the above-described conventional technique in which the pad is provided on the bottom surface of the loading platform, it has been confirmed so far that the frictional force is weakened by vibration during traveling. In addition, it has been confirmed that when earth or sand falls on the frame, the frictional force between the pad and the frame is reduced. Therefore, in this prior art, it is not possible to reduce the forward load applied to the hinge pin over a long period of time.

  Further, in the above-described conventional technology in which a guide is provided below the loading platform, the longitudinal inertial force acting on the loading platform must still be supported by the hinge pin, and therefore the forward load applied to the hinge pin cannot be reduced.

  Further, in the seating device shown in Patent Document 1, it is the hinge pin that supports the inertial force in the front-rear direction that acts on the loading platform. Therefore, even if Patent Document 1 is used, the forward load applied to the hinge pin cannot be reduced.

  In this way, with any of the above-described conventional techniques, most of the longitudinal inertial force acting on the loading platform is supported by the hinge pin, so that it is not possible to reduce the forward load applied to the hinge pin. The situation is facing.

  The present invention has been made in view of the above circumstances, and its purpose is to support at least the forward inertial force of the inertial force acting on the loading platform with a member other than the hinge pin, thereby moving the forward force applied to the hinge pin. The object is to provide a dump truck capable of reducing the load.

  In order to achieve the above object, the present invention provides a dump truck comprising a frame, a hinge pin disposed at a rear portion of the frame, and a loading platform rotatably attached to the frame via the hinge pin. A front stopper structure is provided on the frame to abut against the front portion of the loading platform in a state of being seated on the frame and to support a forward inertial force acting on the loading platform. The front stopper structure is provided on the frame. A front base to be installed, a front abutment plate that abuts the front surface of the cargo bed, a base end side is rotatably coupled to the front base by a first pin, and a front end side is the front contact A first link member rotatably coupled by a contact plate and a second pin, and located on the rear side from the first link member, the base end side is the front base and the third pin A second link member which is coupled so as to be pivotable and has a distal end side coupled to the front abutment plate and a fourth pin so as to be pivotable; and the second link member with the third pin as a center. And a front biasing member that biases in a direction against the direction of seating on the frame, and the loading position of the loading platform starts from a first position where the loading platform is in the middle of rotation of the loading platform. The front abutment plate is driven by the rotation of the cargo bed while being in contact with the front surface portion of the cargo bed.

  According to the present invention, since the forward inertial force acting on the loading platform can be supported by both the front stopper structure and the hinge pin, the forward load applied to the hinge pin can be reduced. Therefore, due to long-term use of the dump truck, there may be a problem in the frame side connecting hole into which the hinge pin is inserted and its surrounding members (for example, the portion where the hinge pin is attached and the surrounding portion of the bottom surface of the loading platform). Is reduced. In addition, it is possible to extend the life and weight of the structure of the connecting portion between the cargo bed and the frame (such as a bracket provided with a frame side connecting hole into which the hinge pin is inserted) and its surrounding members.

  In the present invention, the front urging member is configured to urge the second link member in a direction against the direction in which the cargo bed is seated on the frame with the third pin as the center. The plate can follow the rotation of the loading platform in contact with the front surface of the loading platform. In other words, even if the loading platform is rattled due to long-term use of the dump truck, the front urging member causes the front contact while the loading platform is rotated from the first position to the second position. The contact state between the plate and the front part of the cargo bed is kept good.

  Further, the present invention is the above configuration, wherein the front stopper structure is such that when the loading platform is in the first position, both the second pin and the fourth pin are higher than the third pin, When the loading platform is in the second position, the second pin is configured to be higher than the third pin, and the fourth pin is configured to be positioned lower than the third pin. Of the triangles formed by connecting the centers of the second pin, the third pin, and the fourth pin in the state of the second position, the side connecting the second pin and the fourth pin, and The interior angle formed by the third pin and the side connecting the fourth pin is configured to be an acute angle.

  According to this configuration, when the loading platform is in the second position, the second pin is positioned higher than the third pin, and the fourth pin is positioned lower than the third pin, so that the front contact plate is raised. (See FIG. 7). In addition, among the triangles formed by connecting the centers of the second pin, the third pin, and the fourth pin in that state, the side connecting the second pin and the fourth pin and the side connecting the third pin and the fourth pin The internal angle formed by (see angle α in FIG. 8) is an acute angle. Therefore, even if the loading platform moves slightly from the second position to the first position, it makes it difficult for the front contact plate to immediately rotate (operation to rotate in the direction A in FIG. 7). Can do. In other words, once the loading platform is seated on the frame, the posture of the front abutment plate is less likely to collapse when the loading platform is seated on the frame, even if the loading platform slightly swings up and down. Therefore, for example, even if the loading platform swings up and down slightly from the frame while the dump truck is traveling on an uneven road surface, the front abutment plate does not lose its posture and the forward inertial force acting on the loading platform is firmly maintained. Can be supported.

  The second pin, the third pin, and the fourth pin are arranged in a substantially straight line, so that an inner angle formed by a side connecting the second pin and the fourth pin and a side connecting the third pin and the fourth pin (FIG. 8). It is desirable that the angle α) be substantially zero degrees. This is because the posture of the front abutting plate when the carrier is seated on the frame is more difficult to collapse even if the carrier is slightly swung up and down.

  In the present invention, any front biasing member can be applied, but the following configuration is preferably applied because it is inexpensive and simple in configuration.

  That is, in the above configuration, the front biasing member is a torsion spring, and one end of the torsion spring is held by a holder provided on the front base, and the other end is the first spring. It is preferable that the third pin is wound around in contact with the four pins.

  Further, in the above configuration, the front biasing member is a torsion spring, and one end of the torsion spring contacts the third pin and the other end contacts the front contact plate. It is preferable that the fourth pin is wound around in this state.

  Further, in the above configuration, the front biasing member is a tension spring, and one end of the tension spring is held by the front base, and the other end is the third pin of the second link member. It is preferable that the end portion on the insertion side is held from the position where the third pin is inserted to the position opposite to the position where the fourth pin is inserted.

  Further, in the above configuration, the front biasing member is a pressing spring, one end of the pressing spring is held by the front base, and the other end of the second link member is the third pin. It is preferable that the structure is held at a position between the insertion position and the position where the fourth pin is inserted.

  In the above configuration, a gas spring having a cylinder and a rod that expands and contracts by compressed gas sealed in the cylinder may be employed as the front urging member. In this case, the rear end of the cylinder is attached to the front base, and the tip of the rod is inserted into the second link member at the position where the third pin is inserted and the position where the fourth pin is inserted. The gas spring may be attached to the front stopper structure so that the gas spring is attached to the front stopper structure.

  The rear end of the cylinder is attached to the front contact plate, and the tip of the rod is inserted into the end of the second link member on the side where the third pin is inserted. The gas spring may be attached to the front stopper structure so that the gas spring is attached to a position opposite to the position where the fourth pin is inserted from the position where the fourth pin is inserted.

  Further, the rear end portion of the cylinder is attached to the front base, the tip end portion of the rod is attached to the front contact plate, and the gas spring is attached to the front stopper structure. Also good.

  Further, according to the present invention, in the above configuration, a plurality of the front stopper structures are provided at intervals in the left-right direction when viewed from the front side of the dump truck, and the plurality of front stopper structures It is characterized in that the direction perpendicular to the surface of the contact plate that contacts the front surface portion of the loading platform is parallel to the front-rear direction of the frame when viewed from above.

  According to this configuration, since the forward inertial force acting on the loading platform can be supported by the plurality of front stopper structures, the forward load applied to the hinge pin can be further reduced. In addition, since a plurality of front stopper structures are provided, for example, even if one front stopper structure breaks down and cannot support the forward inertial force acting on the cargo bed, the remaining front stopper structure can be used for the cargo bed. Since the forward inertial force acting on the frame can be supported, there is little possibility that the frame side connection hole into which the hinge pin is inserted or a member around the frame side connection hole.

  Further, according to the present invention, in the above configuration, a plurality of the front stopper structures are provided at intervals in the left-right direction when viewed from the front side of the dump truck, and the plurality of front stopper structures A direction perpendicular to a surface of the abutment plate that abuts on the front surface portion of the cargo bed is installed in a direction that intersects with the front-rear direction of the frame in a top view.

Also with this configuration, the forward inertial force acting on the loading platform can be supported by the plurality of front stopper structures, so that the forward load applied to the hinge pin can be further reduced. In addition, since a plurality of front stopper structures are provided, for example, even if one front stopper structure breaks down and cannot support the forward inertial force acting on the cargo bed, the remaining front stopper structure can be used for the cargo bed. Since the forward inertial force acting on the frame can be supported, there is little possibility that the frame side connection hole into which the hinge pin is inserted or a member around the frame side connection hole. Further, in this configuration, since the front stopper structure is installed in a direction in which the direction perpendicular to the surface of the front contact plate that contacts the front portion of the load carrier intersects with the front-rear direction of the frame when viewed from above, the load carrier It can also support the lateral inertial force acting on the

  Thus, according to the present invention, the inertial force acting on the loading platform of the dump truck can be supported by the stopper structure, so that the load (particularly, the forward load) applied to the hinge pin can be reduced. Therefore, the dump truck can be used for a long time without causing any problems.

It is a side view of the dump truck concerning the 1st example of an embodiment of the present invention. It is a front view which shows the detail of the stopper structure for front shown in FIG. It is AA sectional drawing of the stopper structure for front shown in FIG. It is the side view to which the principal part of the dump truck shown in FIG. 1 was expanded, and the figure which showed the state which has a loading platform in a standing posture. It is the side view which expanded the principal part of the dump truck shown in FIG. 1, and is the figure which showed the state which has a loading platform in the 1st position in the middle of rotation. It is the side view which expanded the principal part of the dump truck shown in FIG. 1, and is the figure which showed the state which has a loading platform in the 2nd position seated on the flame | frame. It is the figure which showed the cross section which cut | disconnected the front stopper structure in the state which has a loading platform in the 2nd position seated on the flame | frame by the AA line shown in FIG. It is the principal part enlarged view which expanded the principal part of the stopper structure for front shown in FIG. It is a figure for demonstrating arrangement | positioning of the stopper structure of the dump truck which concerns on the 2nd Example of this invention. It is a figure for demonstrating arrangement | positioning of the stopper structure of the dump truck which concerns on the 3rd Example of this invention. It is a figure for demonstrating arrangement | positioning of the stopper structure of the dump truck which concerns on the 4th Example of this invention. It is a figure which shows the detail of the stopper structure which concerns on the modification 1 of the dump truck which concerns on the embodiment of this invention, (a) is a sectional side view of the stopper structure in the state which has a loading platform in a standing posture, b) is a sectional side view of the stopper structure in a state where the cargo bed is seated on the frame. It is a figure which shows the detail of the stopper structure which concerns on the modification 2 of the dump truck which concerns on the embodiment of this invention, (a) is a sectional side view of the stopper structure in the state which a loading platform exists in a standing posture, b) is a sectional side view of the stopper structure in a state where the cargo bed is seated on the frame. It is a figure which shows the detail of the stopper structure which concerns on the modification 3 of the dump truck which concerns on embodiment of this invention, (a) is a sectional side view of the stopper structure in the state in which a loading platform exists in a standing posture, b) is a sectional side view of the stopper structure in a state where the cargo bed is seated on the frame. It is a figure which shows the detail of the stopper structure which concerns on the modification 4 of the dump truck which concerns on the embodiment of this invention, (a) is a sectional side view of the stopper structure in the state which has a loading platform in a standing posture, b) is a sectional side view of the stopper structure in a state where the cargo bed is seated on the frame. It is a figure which shows the detail of the stopper structure which concerns on the modification 5 of the dump truck which concerns on the embodiment of this invention, (a) is a sectional side view of the stopper structure in the state which a loading platform exists in a standing posture, b) is a sectional side view of the stopper structure in a state where the cargo bed is seated on the frame. It is a figure which shows the detail of the stopper structure which concerns on the modification 6 of the dump truck which concerns on the embodiment of this invention, (a) is a sectional side view of the stopper structure in the state which has a loading platform in a standing posture, b) is a sectional side view of the stopper structure in a state where the cargo bed is seated on the frame. It is a side view of the dump truck concerning a conventional example.

  A first embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the dump truck according to the first embodiment of the present invention includes a frame 2 forming a main body, a cab 30 disposed at a front position of the frame 2, a front wheel 31 and a rear wheel. A wheel 32, a cargo bed 1 that can be pivoted up and down around a hinge pin 4 provided at a rear portion of the frame 2, and a pair of left and right hoist cylinders 3 that pivot the cargo bed 1 in the vertical direction are provided. Configured. When the operator drives the hoist cylinder 3 from the cab 30, the loading platform 1 is hinged between the lying posture that sits on the frame 2 and the standing posture that releases earth and sand as the hoist cylinder 3 expands and contracts. It is designed to rotate around 4. The hinge pin 4 is inserted into a frame side connecting hole (not shown) provided in the frame 2.

  Although not shown in FIG. 1, the loading platform 1 is provided with a guide 5a (see FIG. 18), and the frame 2 is provided with a guide pad 5b (see FIG. 18) that contacts the guide 5a. When the loading platform 1 rotates around the vertical direction with the loading platform 1 seated on the frame 2 (in other words, when the loading platform 1 moves to the left and right as viewed from the front of the dump truck), the guide 5a Movement of the loading platform 1 in the left-right direction is prevented by contacting the guide pad 5b.

  A stopper pad 12 made of a rubber-based material is provided at the lower part of the front surface portion of the loading platform 1. In addition, a plurality of pads 6 are attached to the bottom surface of the loading platform 1 for mitigating the impact when seated on the frame 2. The pad 6 is made of a rubber material and is formed in a square plate shape. Due to the frictional force between the pad 6 and the frame 2, the loading platform 1 can be seated on the frame 2 in a stable posture.

  Next, the front stopper structure Sf will be described. One front stopper structure Sf is provided on the frame 2, and the installation position is a position slightly ahead of the front surface of the loading platform 1. When the loading platform 1 is seated on the frame 2, the stopper pad 12 of the loading platform 1 and the front stopper structure Sf are in contact with each other (details will be described later).

  As shown in FIGS. 1 to 3, the front stopper structure Sf includes a front base having a base plate 19, a stopper bracket 8 and a stopper bracket 9, and a stopper pad 12 provided on the front surface of the loading platform 1. The stopper plate (front contact plate) 7 to be in contact with the base end side (lower end side) is rotatably coupled by a stopper bracket (front base) 8 and a lower pin (first pin) 16, and the tip end side ( A large adjuster link (first link member) 10 whose upper end side is rotatably coupled by a stopper plate 7 and an upper upper pin (second pin) 17, and a rear side (right side in FIG. 3) from the large adjuster link 10. The base end side (lower end side) is rotatably connected by a stopper bracket (front base) 9 and a spring pin (third pin) 14, The small adjuster link (second link member) 11 whose side (upper end side) is rotatably coupled by the stopper plate 7 and the lower upper pin (fourth pin) 18, the small adjuster link 11, and the spring pin 14 as the center And a spring (front urging member) 13 for urging in a direction (A direction) against the direction (C direction) in which the loading platform 1 is seated on the frame 2.

  The front base of the present embodiment is configured by providing a pair of stopper brackets 8 on the front side of the base plate 19 and a pair of stopper brackets 9 on the rear side of the base plate 19. It is a part installed on the frame 2. The stopper plate 7 is formed in a rectangular plate shape, the surface is a contact surface that contacts the stopper pad 12, and the upper upper pin 17 and the lower upper pin 18 are attached to the back surface side. As shown in FIG. 2, the large adjuster link 10 is composed of a pair of left and right arm-shaped members, and the small adjuster link 11 is also composed of a pair of left and right arm-shaped members. As described above, the front stopper structure Sf includes a four-link mechanism in which the large adjuster link 10, the small adjuster link 11, and the stopper plate 7 rotate through the four pins 14, 16, 17, and 18. It is.

  The spring 13 is a torsion spring wound around the spring pin 14. One end of the spring 13 is held by a holder 15 provided on a base plate (front base) 19, and the other end is It is in contact with the lower upper pin 18. Therefore, the small adjuster link 11 is always urged in the A direction by the spring 13 around the spring pin 14. That is, when the loading platform 1 stands up from the frame 2 (see FIG. 4), the stopper plate 7 is maintained in a state in which the surface faces slightly upward as shown in FIG. In this state, the upper upper pin 17 and the lower upper pin 18 are both higher than the spring pin 14.

  Next, the operation of the front stopper structure Sf will be described with reference to FIGS. When the loading platform 1 is rotated in the C direction so as to gradually change from the standing posture shown in FIG. 4 to the first position shown in FIG. 5, the stopper pad 12 is moved to the front stopper. The contact with the stopper plate 7 of the structure Sf is started. At this time, the stopper plate 7 is urged in the A direction by the spring 13 as shown in FIG. When the loading platform 1 is further rotated in the C direction from the first position shown in FIG. 5, the stopper plate 7 is rotated in the C direction while holding the stopper plate 7 in contact with the stopper pad 12 by the spring 13. Accordingly, the large adjuster link 10 passively rotates in the direction B in the figure around the lower pin 16, and the small adjuster passively rotates in the direction B in the figure around the spring pin 14.

  Then, when the loading platform 1 is seated on the frame 2 as shown in FIG. 6, due to the weight of the loading platform 1 (the load applied in the L direction in FIG. 7), the stopper plate 7 causes the urging force of the spring 13 as shown in FIG. Against this, it is rotated in the direction B and held upright. In this state, the upper upper pin 17 is at a position higher than the spring pin 14, but the lower upper pin 18 is at a position lower than the spring pin 14. That is, the height relationship among the upper upper pin 17, the lower upper pin 18 and the spring pin 14 is changed by the rotation of the stopper plate 7 accompanying the rotation of the loading platform 1. In the state of FIG. 6, the loading platform 1 is prevented from moving forward by the front stopper structure Sf.

  Here, the posture of the front stopper structure Sf in a state where the loading platform 1 is seated on the frame 2 as shown in FIG. 6 will be described in detail with reference to FIG. FIG. 8 shows the position of the front stopper structure Sf in a state where the loading platform 1 is seated on the frame 2, and the portion where the stopper plate 7 and the large adjuster link 10 are pin-coupled, the stopper plate 7 and the small This is an enlarged view of a portion (main part) where the adjuster link 11 is pin-coupled.

  As shown in FIG. 8, when the load carrier 1 is seated on the frame 2, a triangle formed by connecting the center of the upper upper pin 17, the center of the spring pin 14 and the center of the lower upper pin 18 (two in FIG. 8). (A figure drawn with a dotted line) is formed by a side connecting the center of the upper upper pin 17 and the center of the lower upper pin 18 and a side connecting the center of the spring pin 14 and the center of the lower upper pin 18. The posture of the front stopper structure Sf is maintained so that the inner angle α is an acute angle. Further, a front stopper structure is formed such that an inner angle β formed by a side connecting the center of the upper upper pin 17 and the center of the spring pin 14 and a side connecting the spring pin 14 and the lower upper pin 18 becomes an obtuse angle. The posture of Sf is maintained.

  Now, assuming that the front stopper structure Sf is held in the posture shown in FIG. 7, when the loading platform 1 moves slightly from the second position to the first position, that is, Consider the movement of the front stopper structure Sf when the loading platform 1 is slightly lifted. When the loading platform 1 is lifted, the load applied to the stopper plate 7 disappears, so that the small adjuster link 11 tries to rotate in the A direction about the spring pin 14 by the urging force of the spring 13. However, the inner angle α formed by the side connecting the center of the upper upper pin 17 and the center of the lower upper pin 18 and the side connecting the center of the spring pin 14 and the center of the lower upper pin 18 is an acute angle. It is difficult to smoothly rotate the small adjuster link 11 in the A direction around the spring pin 14. That is, it can be said that it is rare that the posture in which the stopper plate 7 stands as shown in FIG.

  Therefore, even if the loading platform 1 is slightly lifted from the second position, the stopper plate 7 can be reliably brought into contact with the stopper pad 12 when the loading platform 1 is seated on the frame 2 again. Therefore, even if the loading platform 1 is slightly lifted due to vibration or the like during traveling of the dump truck, the front stopper structure Sf can reliably support the forward inertial force applied to the loading platform 1.

  Thus, according to the dump truck according to the first embodiment, even if a forward inertial force acts on the loading platform 1 due to a sudden brake or the like, the front stopper structure Sf receives the inertial force. A large load is not applied to the hinge pin 4. Therefore, even if the dump truck is used for a long period of time, there are few problems that occur in the frame side connecting hole into which the hinge pin 4 is inserted and the members around it. In addition, since the stopper plate 7 is rotated by the above-described four-bar linkage mechanism, even if the carrier 1 is rattled, the stopper plate 7 contacts the stopper pad 12 at a suitable angle while the carrier 1 is rotated. be able to. Moreover, after the stopper plate 7 is rotated until the loading platform 1 is seated on the frame 2, even if the loading platform 1 moves slightly up and down from the second position, the posture of the stopper pad 7 is collapsed by the above-described four-bar linkage mechanism. Since it becomes difficult, the inertia force of the front direction which acts on the loading platform 1 can be supported reliably.

  In the first embodiment described above, the spring 13 employs a torsion spring, but may be replaced with a push spring, a pull spring, a leaf spring, or other springs. Further, the small adjuster link 11 may be passively rotated using a permanent magnet instead of the configuration of the spring 13. Further, an actuator may be installed to actively rotate the small adjuster link 11.

  Next, the dump truck according to the second embodiment of the present invention will be described. The same components as those of the dump truck according to the first embodiment are denoted by the same reference numerals, and the description will be made. Is omitted. As shown in FIG. 9, the front stopper structure Sf is spaced in the left-right direction (up-down direction in FIG. 9) when viewed from the front side of the dump truck, in the frame 2 of the dump truck according to the second embodiment. Two are provided. In the two front stopper structures Sf, the direction perpendicular to the surface of the stopper plate 7 that contacts the stopper pad 12 of the loading platform 1 (the direction of arrow D in FIG. 9) is the front-rear direction of the dump truck (left and right in FIG. 9). And the stopper plate 7 are arranged so as to be parallel to each other when viewed from above.

  According to the second embodiment, the two front stopper structures Sf support the forward inertial force acting on the cargo bed 1 even if the forward inertial force is applied to the cargo bed 1 due to sudden braking or the like. Therefore, the load applied to the hinge pin 4 is greatly reduced. Therefore, even if the dump truck is used for a long period of time, there are few problems that occur in the frame side connecting hole into which the hinge pin 4 is inserted and the members around it. Moreover, since two front stopper structures Sf are provided, even if one front stopper structure Sf fails, the front inertial force acting on the loading platform 1 by the other front stopper structure Sf is increased. Can be supported.

  Next, a dump truck according to a third embodiment of the present invention will be described. The same components as those of the dump truck according to the first embodiment are denoted by the same reference numerals, and the description thereof will be made. Is omitted. In the frame 2 of the dump truck according to the third embodiment, as shown in FIG. 10, the front stopper structure Sf is spaced in the left-right direction (vertical direction in FIG. 10) as viewed from the front side of the dump truck. Two are provided. One of the two front stopper structures Sf has a direction (indicated by an arrow E1 in FIG. 10) perpendicular to the surface of the stopper plate 7 that contacts the stopper pad 12 of the loading platform 1 (the direction of the arrow E1 in FIG. 10). 10 is a direction intersecting with the top view, in other words, in other words, the surface of the stopper plate 7 is arranged so as to face the rear and inner direction of the dump truck.

  In the other front stopper structure Sf, the direction perpendicular to the surface of the stopper plate 7 that contacts the stopper pad 12 of the loading platform 1 (the direction of arrow E2 in FIG. 10) is the front-rear direction of the dump truck (left and right in FIG. 10). Direction) in a top view, in other words, the surface of the stopper plate 7 is arranged so as to face the rear and the inner side of the dump truck. The direction of the stopper plate 7 is different from that of the second embodiment.

  According to the third embodiment, since the stopper plates 7 are attached to each other inwardly, even if a forward inertial force is applied to the loading platform 1 by a sudden brake or the like, two front stopper structures are provided. Sf can support the inertial force acting on the loading platform 1. Moreover, since the stopper plate 7 faces inward, even if a centrifugal force acts on the loading platform 1 in the lateral direction of the vehicle body while the dump truck is turning, the centrifugal force can be supported by the front stopper structure Sf. Therefore, the load applied to the hinge pin 4 is greatly reduced.

  Next, a dump truck according to a fourth embodiment of the present invention will be described. The same components as those of the dump truck according to the first embodiment are denoted by the same reference numerals, and the description thereof will be made. Is omitted. As shown in FIG. 11, the front stopper structure Sf is spaced in the left-right direction (vertical direction in FIG. 11) when viewed from the front side of the dump truck, in the frame 2 of the dump truck according to the fourth embodiment. Two are provided. In one of the two front stopper structures Sf, the direction (in the direction of arrow F1 in FIG. 11) perpendicular to the surface of the stopper plate 7 that contacts the stopper pad 12 of the loading platform 1 is the front-rear direction of the dump truck (see FIG. 11 is a direction intersecting with the top view, in other words, the surface of the stopper plate 7 is arranged so as to face the rear side and the outer side of the dump truck.

  In the other front stopper structure Sf, the direction perpendicular to the surface of the stopper plate 7 that contacts the stopper pad 12 of the loading platform 1 (the direction of the arrow F2 in FIG. 11) is the front-rear direction of the dump truck (FIG. 11). In this case, the stopper plate 7 is disposed so that the surface of the stopper plate 7 faces the rear side and the outer side of the dump truck. The direction of the stopper plate 7 is opposite to that of the third embodiment.

  The same effect as that of the third embodiment can be obtained with the fourth embodiment. That is, since the stopper plates 7 are attached to each other so as to be inclined outwardly, the two front stopper structures Sf support the inertial force that acts on the cargo bed 1 even if a forward inertial force acts on the cargo bed 1 due to sudden braking or the like. it can. Moreover, since the stopper plate 7 faces outward, even if a centrifugal force acts on the loading platform 1 in the lateral direction of the vehicle body while the dump truck is turning, the centrifugal force can be supported by the front stopper structure Sf. Therefore, the load applied to the hinge pin 4 is greatly reduced.

  In the above-described embodiment, the front stopper structure Sf is provided on the frame 2 and the stopper pad that contacts the stopper structure Sf is provided on the loading platform 1. However, the stopper pad is provided on the frame 2 and the stopper structure Sf is disposed on the loading platform. 1 may be provided.

  Next, a modification suitable as a front stopper structure applied to the dump truck according to the embodiment of the present invention will be described in detail with reference to the drawings. In addition, about the thing of the same structure as the front stopper structure Sf mentioned above, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

(Modification 1)
In the front stopper structure Sf1 according to the first modification shown in FIG. 12, a torsion spring is used as the front biasing member. The spring 13 which is a torsion spring is attached in a state of being wound around the lower upper pin 18. One end of the spring 13 is in contact with the spring pin 14, and the other end is in contact with the back surface of the stopper plate 7. Therefore, the small adjuster link 11 is always urged in the A direction about the spring pin 14 by the spring 13, and as shown in FIG. 12A, when the loading platform 1 stands up from the frame 2, the stopper plate 7 will be maintained in a state where the surface is slightly upward. When the loading platform 1 rotates in the direction in which the loading platform 1 is seated on the frame 2, the rotation of the loading platform 1 causes the stopper plate 7 to rotate in the B direction against the urging force of the spring 13. During this time, the contact state between the stopper pad 12 and the stopper plate 7 on the front surface portion of the loading platform 1 is well maintained by the urging force of the spring 13. When the loading platform 1 is seated on the frame 2, the stopper plate 7 is held up by the load applied in the L direction of the loading platform 1 as shown in FIG. In this state, the loading platform 1 is prevented from moving forward by the front stopper structure Sf1.

  Also in the front stopper structure Sf1 according to the first modification, when the loading platform 1 is seated on the frame 2, as shown in FIG. 12B, the center of the upper upper pin 17, the center of the spring pin 14, and the lower upper pin. Among the triangles formed by connecting the centers of 18, the side connecting the center of the upper upper pin 17 and the center of the lower upper pin 18, and the side connecting the center of the spring pin 14 and the center of the lower upper pin 18. The formed internal angle α is an acute angle. Further, an internal angle β formed by a side connecting the center of the upper upper pin 17 and the center of the spring pin 14 and a side connecting the spring pin 14 and the lower upper pin 18 (not shown in FIG. 12B). The posture of the front stopper structure Sf1 is maintained so that the angle becomes obtuse.

  Therefore, even if the loading platform 1 is slightly lifted from the second position shown in FIG. 12B, it is rare that the stopper plate 7 immediately breaks the posture of FIG. Therefore, when the loading platform 1 is seated on the frame 2 again, the stopper plate 7 can be reliably brought into contact with the stopper pad 12. That is, even if the loading platform 1 is slightly lifted due to vibration during the traveling of the dump truck, the front stopper structure Sf1 can reliably support the forward inertial force applied to the loading platform 1.

(Modification 2)
In the front stopper structure Sf2 according to the second modification shown in FIG. 13, a tension spring is used as the front urging member. A spring 22 as a tension spring is attached so as to connect the small adjuster link 11 and the stopper bracket 9. One end of the spring 22 is held by a locking pin 21 provided on the stopper bracket 9, and the other end is held by a locking pin 20 provided on the small adjuster link 11. The position where the locking pin 20 is provided is the position where the lower upper pin 18 is inserted from the position where the spring pin 14 is inserted into the end of the small adjuster link 11 on the side where the spring pin 14 is inserted. It is a position on the opposite side (in other words, of the end of the small adjuster link 11 on the side where the spring pin 14 is inserted, the position closer to the tip than the position where the spring pin 14 is inserted). On the other hand, the locking pin 21 is provided at a position below the stopper bracket 9 and in front of the spring pin 14 (left side in FIG. 13A). In a state where 1 is standing from the frame 2 (the state shown in FIG. 13A), it is on a straight line connecting the lower upper pin 18, the spring pin 14, and the locking pin 20 and below the locking pin 20. It is provided in the position.

  According to the second modification, the small adjuster link 11 is always urged in the A direction about the spring pin 14 by the spring 22, and the loading platform 1 stands up from the frame 2 as shown in FIG. In this posture, the stopper plate 7 is maintained in a state where the surface is slightly upward. When the loading platform 1 rotates in the direction in which the loading platform 1 is seated on the frame 2, the rotation of the loading platform 1 causes the stopper plate 7 to rotate in the B direction against the urging force of the spring 22. During this time, the contact state between the stopper pad 12 and the stopper plate 7 on the front surface of the loading platform 1 is well maintained by the urging force of the spring 22. When the loading platform 1 is seated on the frame 2, the stopper plate 7 is held up by the load applied in the L direction of the loading platform 1 as shown in FIG. In this state, the loading platform 1 is prevented from moving forward by the front stopper structure Sf2.

  Also in the front stopper structure Sf2 according to the modified example 2, when the loading platform 1 is seated on the frame 2, as shown in FIG. 13B, the center of the upper upper pin 17, the center of the spring pin 14, and the lower upper pin. Among the triangles formed by connecting the centers of 18, the side connecting the center of the upper upper pin 17 and the center of the lower upper pin 18, and the side connecting the center of the spring pin 14 and the center of the lower upper pin 18. The formed internal angle α is an acute angle. Further, an inner angle β formed by a side connecting the center of the upper upper pin 17 and the center of the spring pin 14 and a side connecting the spring pin 14 and the lower upper pin 18 (not shown in FIG. 13B). The posture of the front stopper structure Sf2 is maintained so that becomes an obtuse angle.

  Therefore, even if the loading platform 1 is slightly lifted from the second position shown in FIG. 13B, it is rare that the stopper plate 7 immediately breaks the posture of FIG. 13B. Therefore, when the loading platform 1 is seated on the frame 2 again, the stopper plate 7 can be reliably brought into contact with the stopper pad 12. That is, even if the loading platform 1 is slightly lifted due to vibration or the like during traveling of the dump truck, the front stopper structure Sf2 can reliably support the forward inertial force applied to the loading platform 1.

(Modification 3)
In the front stopper structure Sf3 according to the third modification shown in FIG. 14, a pressing spring is used as the front urging member. A spring 32 that is a push spring is attached so as to connect the small adjuster link 11 a and the stopper bracket 9. One end of the spring 32 is held by a bracket 31 provided on the stopper bracket 9, and the other end is held by a bracket 30 provided on the small adjuster link 11a. In the third modification, the small adjuster link 11a has a shape in which one side is curved outward and swelled.

  The position where the bracket 30 is provided is a position between the position where the spring pin 14 is inserted and the position where the lower upper pin 18 is inserted in the small adjuster link 11a and is curved outward and swelled. It is the position near the side of the side. On the other hand, the bracket 31 is provided at a position below the stopper bracket 9 and in front of the spring pin 14 (left side in FIG. 14A).

  In the third modification, the guide bar 33 is inserted into the spring 32. The guide bar 33 is axially bent without bending so that the spring 32 buckles in the process of the stopper plate 7 being displaced. It is for making it expand and contract smoothly. Depending on the size and characteristics of the spring 32, the guide bar 33 may not necessarily be provided.

  According to the third modification, the small adjuster link 11a is always urged in the A direction about the spring pin 14 by the spring 32, and the loading platform 1 stands up from the frame 2 as shown in FIG. In this posture, the stopper plate 7 is maintained in a state where the surface is slightly upward. When the loading platform 1 rotates in the direction in which the loading platform 1 is seated on the frame 2, the rotation of the loading platform 1 causes the stopper plate 7 to rotate in the B direction against the urging force of the spring 32. During this time, the contact state between the stopper pad 12 and the stopper plate 7 on the front surface of the loading platform 1 is maintained well by the biasing force of the spring 32. When the loading platform 1 is seated on the frame 2, as shown in FIG. 14B, the stopper plate 7 is held up by the load applied to the loading platform 1 in the L direction. In this state, the loading platform 1 is prevented from moving forward by the front stopper structure Sf3.

  Also in the front stopper structure Sf3 according to the third modification example, when the loading platform 1 is seated on the frame 2, as shown in FIG. 14B, the center of the upper upper pin 17, the center of the spring pin 14, and the lower upper pin. Among the triangles formed by connecting the centers of 18, the side connecting the center of the upper upper pin 17 and the center of the lower upper pin 18, and the side connecting the center of the spring pin 14 and the center of the lower upper pin 18. The formed internal angle α is an acute angle. Further, an inner angle β formed by a side connecting the center of the upper upper pin 17 and the center of the spring pin 14 and a side connecting the spring pin 14 and the lower upper pin 18 (not shown in FIG. 14B). The posture of the front stopper structure Sf3 is maintained so that becomes an obtuse angle.

  Therefore, even if the loading platform 1 is slightly lifted from the second position shown in FIG. 14B, it is rare that the stopper plate 7 immediately breaks the posture of FIG. 14B. Therefore, when the loading platform 1 is seated on the frame 2 again, the stopper plate 7 can be reliably brought into contact with the stopper pad 12. That is, even if the loading platform 1 is slightly lifted due to vibration or the like during the traveling of the dump truck, the front stopper structure Sf3 can reliably support the forward inertial force applied to the loading platform 1.

(Modification 4)
In the front stopper structure Sf4 according to the modified example 4 shown in FIG. 15, a gas spring 42 is used as a front biasing member instead of a spring. The gas spring 42 has a cylinder 42a and a rod 42b that expands and contracts by the compressed gas sealed in the cylinder 42a, and the rod 42b expands and contracts by compression / expansion of the compressed gas. The rear end of the cylinder 42a is attached to a bracket 41 provided on the stopper bracket 9, and the tip of the rod 42b is attached to a bracket 40 provided on the small adjuster link 11a. In the fourth modification, the small adjuster link 11a has a shape in which one side is curved outward and swelled.

  The position where the bracket 40 is provided is a position between the position where the spring pin 14 is inserted and the position where the lower upper pin 18 is inserted in the small adjuster link 11a, and bulges by bending outward. It is the position near the side of the side. On the other hand, the bracket 41 is provided at a position below the stopper bracket 9 and in front of the spring pin 14 (left side in FIG. 15A).

  According to the fourth modification, the small adjuster link 11a is always urged in the A direction about the spring pin 14 by the force by which the rod 42b of the gas spring 42 extends, as shown in FIG. 15 (a). In addition, when the loading platform 1 stands up from the frame 2, the stopper plate 7 is maintained in a state where the surface faces slightly upward. When the loading platform 1 rotates in the direction in which it is seated on the frame 2, the stopper plate 7 follows the rotation of the loading platform 1, and the stopper plate 7 pushes the rod 42b of the gas spring 42 into the cylinder 42a via the small adjuster link 11a. Rotate to. During this time, the contact state between the stopper pad 12 and the stopper plate 7 on the front surface of the loading platform 1 is well maintained by the urging force of the gas spring 42. When the loading platform 1 is seated on the frame 2, the stopper plate 7 is held in a raised state by the load applied in the L direction of the loading platform 1 as shown in FIG. In this state, the loading platform 1 is prevented from moving forward by the front stopper structure Sf4.

  Also in the front stopper structure Sf4 according to the modified example 4, when the loading platform 1 is seated on the frame 2, as shown in FIG. 15B, the center of the upper upper pin 17, the center of the spring pin 14, and the lower upper pin. Among the triangles formed by connecting the centers of 18, the side connecting the center of the upper upper pin 17 and the center of the lower upper pin 18, and the side connecting the center of the spring pin 14 and the center of the lower upper pin 18. The formed internal angle α is an acute angle. Further, an inner angle β formed by a side connecting the center of the upper upper pin 17 and the center of the spring pin 14 and a side connecting the spring pin 14 and the lower upper pin 18 (not shown in FIG. 15B). The posture of the front stopper structure Sf4 is maintained so that becomes an obtuse angle.

  Therefore, even if the loading platform 1 is slightly lifted from the second position shown in FIG. 15B, it is rare that the stopper plate 7 immediately breaks the posture of FIG. 15B. Therefore, when the loading platform 1 is seated on the frame 2 again, the stopper plate 7 can be reliably brought into contact with the stopper pad 12. That is, even if the loading platform 1 is slightly lifted due to vibration or the like during traveling of the dump truck, the front stopper structure Sf4 can reliably support the forward inertial force applied to the loading platform 1.

(Modification 5)
In the front stopper structure Sf5 according to the modified example 5 shown in FIG. 16, a gas spring 52 is used as a front biasing member instead of a spring. The gas spring 52 has a cylinder 52a and two rods 52b and 52c that are expanded and contracted by compressed gas sealed in the cylinder 52a, and the rods 52b and 52c are expanded and contracted by compression / expansion of the compressed gas. It has become. The rear end of the cylinder 52 a is attached to a bracket 50 provided on the back surface of the stopper plate 7, and the tip of the rod 52 b is provided on a bracket 51 provided on the small adjuster link 11.

  The position where the bracket 51 is provided is opposite to the position where the lower upper pin 18 is inserted from the position where the spring pin 14 is inserted in the end of the small adjuster link 11 on the side where the spring pin 14 is inserted. (In other words, of the end of the small adjuster link 11 on the side where the spring pin 14 is inserted, the position closer to the tip than the position where the spring pin 14 is inserted). On the other hand, the bracket 50 is provided on the back surface of the stopper plate 7 and at a position between the upper upper pin 17 and the lower upper pin 18.

  According to the fifth modification, the small adjuster link 11 is always urged in the A direction around the spring pin 14 by the force by which the rods 52b and 52c of the gas spring 52 extend, as shown in FIG. As shown, when the loading platform 1 stands up from the frame 2, the stopper plate 7 is maintained in a state where the surface faces slightly upward. When the loading platform 1 rotates in the direction in which the loading platform 1 is seated on the frame 2, the stopper plate 7 pushes the rods 52b and 52c of the gas spring 52 through the small adjuster link 11 in the direction F in the figure. While rotating in the B direction. During this time, the contact state between the stopper pad 12 and the stopper plate 7 on the front surface of the loading platform 1 is maintained well by the urging force of the gas spring 52. When the loading platform 1 is seated on the frame 2, the stopper plate 7 is held up by the load applied in the L direction of the loading platform 1 as shown in FIG. In this state, the loading platform 1 is prevented from moving forward by the front stopper structure Sf5.

  Also in the front stopper structure Sf5 according to the modified example 5, when the loading platform 1 is seated on the frame 2, as shown in FIG. 16B, the center of the upper upper pin 17, the center of the spring pin 14, and the lower upper pin. Among the triangles formed by connecting the centers of 18, the side connecting the center of the upper upper pin 17 and the center of the lower upper pin 18, and the side connecting the center of the spring pin 14 and the center of the lower upper pin 18. The formed internal angle α is an acute angle. Further, an inner angle β formed by a side connecting the center of the upper upper pin 17 and the center of the spring pin 14 and a side connecting the spring pin 14 and the lower upper pin 18 (not shown in FIG. 16B). The posture of the front stopper structure Sf5 is maintained so that becomes an obtuse angle.

  Therefore, even if the loading platform 1 is slightly lifted from the second position shown in FIG. 16B, it is rare that the stopper plate 7 immediately breaks the posture of FIG. Therefore, when the loading platform 1 is seated on the frame 2 again, the stopper plate 7 can be reliably brought into contact with the stopper pad 12. That is, even if the loading platform 1 is slightly lifted due to vibration during the running of the dump truck, the front stopper structure Sf5 can reliably support the forward inertial force applied to the loading platform 1.

(Modification 6)
In the front stopper structure Sf6 according to the modified example 6 shown in FIG. 17, a gas spring 62 is used instead of the spring as the front biasing member. The gas spring 62 includes a cylinder 62a and a rod 62b that expands and contracts by compressed gas sealed in the cylinder 62a, and the rod 62b expands and contracts by compression / expansion of the compressed gas.

  The stopper bracket 9 is provided with a small piece 9a extending from the upper part toward the front side, and the small piece 9a is provided with a bracket 61 for holding the rear end portion of the cylinder 62a. The bracket 61 is located between the spring pin 14 and the lower upper pin 18 at a position in front of the spring pin 14 and in a state in which the loading platform 1 is standing from the frame 2 (the state shown in FIG. 17A). It is provided at a position where the height is between. On the other hand, a bracket 60 is provided on the back surface of the stopper plate 7 and between the upper upper pin 17 and the lower upper pin 18, and the tip of the rod 62 b is held by the bracket 60. In the state of FIG. 17B, the positions of the bracket 60 and the bracket 61 are determined so that the gas spring 62 is perpendicular to the surface of the stopper plate 7 (the contact surface that contacts the stopper pad 12). Yes.

  According to the sixth modification, the small adjuster link 11 is always urged in the A direction around the spring pin 14 by the force that the rod 62b of the gas spring 62 extends in the F direction shown in FIG. As shown in FIG. 17 (a), when the loading platform 1 stands up from the frame 2, the stopper plate 7 is maintained in a state where the surface faces slightly upward. When the loading platform 1 rotates in the direction in which the loading platform 1 is seated, the loading plate 1 is rotated, and the stopper plate 7 rotates in the B direction while pushing the rod 62b of the gas spring 62 in the direction opposite to the F direction in the figure. I will do it. During this time, the contact state between the stopper pad 12 and the stopper plate 7 on the front surface of the loading platform 1 is maintained well by the biasing force of the gas spring 62. When the loading platform 1 is seated on the frame 2, the stopper plate 7 is held in a raised state by the load applied in the L direction of the loading platform 1, as shown in FIG. In this state, the loading platform 1 is prevented from moving forward by the front stopper structure Sf6.

  Also in the front stopper structure Sf6 according to the modified example 6, when the loading platform 1 is seated on the frame 2, as shown in FIG. 17B, the center of the upper upper pin 17, the center of the spring pin 14, and the lower upper pin. Among the triangles formed by connecting the centers of 18, the side connecting the center of the upper upper pin 17 and the center of the lower upper pin 18, and the side connecting the center of the spring pin 14 and the center of the lower upper pin 18. The formed internal angle α is an acute angle. Further, an inner angle β formed by a side connecting the center of the upper upper pin 17 and the center of the spring pin 14 and a side connecting the spring pin 14 and the lower upper pin 18 (not shown in FIG. 17B). The posture of the front stopper structure Sf5 is maintained so that becomes an obtuse angle.

  Therefore, even if the loading platform 1 is slightly lifted from the second position shown in FIG. 17B, it is rare that the stopper plate 7 immediately breaks the posture of FIG. 17B. Therefore, when the loading platform 1 is seated on the frame 2 again, the stopper plate 7 can be reliably brought into contact with the stopper pad 12. That is, even if the loading platform 1 is slightly lifted due to vibration during the traveling of the dump truck, the front stopper structure Sf6 can reliably support the forward inertial force applied to the loading platform 1.

  Of course, the front stopper structures Sf1 to Sf6 according to the first to sixth modifications described above can be provided on the left and right as viewed from the front as shown in FIGS. Needless to say, any of the directions D, E1, E2, F1, and F2 shown in FIGS. 9 to 11 can be applied to the structures Sf1 to Sf6.

1 Loading platform 2 Frame 3 Hoist cylinder 4 Hinge pin 7 Stopper plate (front contact plate)
8, 9 Stopper bracket (front base)
10 Large adjuster link (first link member)
11 Small adjuster link (second link member)
12 Stopper pad 13, 22, 32 Spring (front biasing member)
14 Spring pin (3rd pin)
15 Spring holder (holder)
16 Lower pin (first pin)
17 Upper pin (second pin)
18 Lower upper pin (4th pin)
19 Base plate (base for front)
Sf, Sf1-Sf6 Front stopper structure

Claims (8)

In a dump truck comprising a frame, a hinge pin arranged at the rear of the frame, and a loading platform that is pivotally attached to the frame via the hinge pin,
A front stopper structure for supporting a forward inertial force acting on the loading platform in contact with the front surface portion of the loading platform in a state of being seated on the frame is provided on the frame,
The front stopper structure is:
A front base installed on the frame;
A front abutment plate that abuts against the front surface of the cargo bed;
A first link member whose base end side is rotatably coupled to the front base by a first pin, and whose distal end side is rotatably coupled to the front contact plate and a second pin;
Located on the rear side of the first link member, the base end side is rotatably connected by the front base and the third pin, and the front end side is rotatably connected by the front contact plate and the fourth pin. A second link member,
A front urging member that urges the second link member in a direction against the direction in which the cargo bed is seated on the frame about the third pin;
When the rotation position of the loading platform is in a range from a first position in the middle of rotation of the loading platform to a second position where the loading platform is seated with the frame, the front contact plate is A dump truck characterized by being driven by the rotation of the loading platform in contact with the front surface of the loading platform. In the description of claim 1,
In the front stopper structure, when the loading platform is in the first position, the second pin and the fourth pin are both higher than the third pin, and when the loading platform is in the second position. The second pin is configured to be higher than the third pin, and the fourth pin is configured to be lower than the third pin, and the loading platform is in the second position. Of the triangles formed by connecting the centers of the second pin, the third pin, and the fourth pin, the side connecting the second pin and the fourth pin, and the third pin and the fourth pin are connected. A dump truck characterized in that an inner angle formed by a side is an acute angle. In the description of claim 1 or 2,
The front urging member is a torsion spring, and the torsion spring has one end held by a holder provided on the front base and the other end in contact with the fourth pin. The dump truck is wound around the third pin. In the description of claim 1 or 2,
The front biasing member is a torsion spring, and the torsion spring has one end abutting on the third pin and the other end abutting on the front abutting plate. A dump truck that is wound around 4 pins. In the description of claim 1 or 2,
The front biasing member is a tension spring. One end of the tension spring is held by the front base, and the other end is an end of the second link member on the side where the third pin is inserted. The portion is held from the position where the third pin is inserted to the position opposite to the position where the fourth pin is inserted.
A dump truck characterized by that. In the description of claim 1 or 2,
The front biasing member is a pressing spring, and one end of the pressing spring is held by the front base, and the other end of the second link member is inserted into the position where the third pin is inserted. A dump truck characterized by being held at a position between positions where the fourth pin is inserted. In description of any one of Claims 1-6,
A plurality of the front stopper structures are provided at intervals in the left-right direction when viewed from the front side of the dump truck, and the plurality of front stopper structures are front portions of the loading platform among the front contact plates. A dump truck characterized in that a direction perpendicular to a surface in contact with the frame is parallel to the front-rear direction of the frame as viewed from above. In description of any one of Claims 1-6,
A plurality of the front stopper structures are provided at intervals in the left-right direction when viewed from the front side of the dump truck, and the plurality of front stopper structures are front portions of the loading platform among the front contact plates. A dump truck characterized in that a direction perpendicular to a surface in contact with the frame intersects with the front-rear direction of the frame in a top view.

Images