JP2016107928A - Dump truck - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dump truck capable of reducing a load on a mount part of a power unit due to the twist of a vehicle body frame, and achieving a lightweight structure of the vehicle body frame and the mount part of the power unit.SOLUTION: A dump truck comprises a pair of side frames 2b, 2e and a power unit 13 supported between the side frames 2b, 2e. A support structure for supporting the power unit 13 on the side frames 2b, 2e comprises first support parts 32, 42 and second support parts 31, 41 for supporting the power unit 13 on the side frames 2b, 2e. The first support parts 32, 42 and the second support parts 31, 41 have connection parts for supporting the power unit 13 rotatably with respect to the side frames 2b, 2e so that rotation centers around a vehicle body longitudinal direction axis are located between the power unit 13 and each side frame 2b, 2e in a vehicle width direction.SELECTED DRAWING: Figure 5A

Description

  The present invention relates to a dump truck that transports objects to be transported such as earth and sand, and more particularly to a frame structure that reduces the load stress of a power unit mount.

  As a background art in this technical field, there is JP 2008-149888 (Patent Document 1). This publication states that “support of a power plant (power unit) that can sufficiently improve frame rigidity while preventing damage to the engine support due to torsional or bending deformation of the left and right side frames when the vehicle is turning. A structure is provided in which a pair of side frames are extended in the vehicle longitudinal direction at intervals in the vehicle width direction and a mounting bracket is attached, and both mounting brackets are connected to each other by a support cross member. Produced into a substantially rectangular cross-section with the long side in the vertical direction, the support cross member is made to oppose the vertical bending load input from the side frame to improve the frame rigidity, while the front and back bends due to the deformation of the side frame during turning For the load, the support cross member is bent to prevent breakage. ” ).

JP 2008-149888 A

  In the support structure of Patent Document 1, since the support cross member having a substantially rectangular cross section is installed between the side frames, the weight of the vehicle body increases, and the transport efficiency decreases. In particular, in an ultra-large dump truck used in a mine or the like, the distance between a pair of side frames installed at a distance in the vehicle width direction is wider than a truck traveling on a general road. Therefore, when the support structure of Patent Document 1 is adopted for a dump truck used in a mine or the like, the support cross member installed between the pair of side frames is increased in size, and the increase in the weight of the vehicle body is increased.

  Further, when the vehicle travels in a place where the road surface is uneven, the frame is twisted. For example, when only the left front tire climbs the step, the left front tire mounting part will be higher than the remaining right front and left and right rear tire mounting parts, so the pair of left and right side frames will deform so that a large displacement difference occurs in the vertical direction. And When the vertical displacement difference between the left and right side frames is opposed by the support cross member, a large load is applied to the joint between the support cross member and the mount bracket or the joint between the mount bracket and the side frame. There is a possibility of damage at the load site.

  An object of the present invention is to provide a dump truck that can reduce a load applied to a mount portion (support structure portion) of a power unit due to torsion of a vehicle body frame, and can achieve a lightweight structure between the vehicle body frame and the mount portion of the power unit.

In order to solve the above problems, a dump truck according to the present invention is supported between a pair of left and right side frames extending in the longitudinal direction of the vehicle body at intervals in the vehicle width direction, and the pair of left and right side frames. In a dump truck with a power unit,
The support structure for supporting the power unit on the pair of left and right side frames includes a first support part for supporting the power unit on a left side frame, and a second support part for supporting the power unit on a right side frame,
The first support portion rotates the power unit with respect to the left side frame so that the center of rotation about the vehicle longitudinal axis is positioned between the power unit and the left side frame in the vehicle width direction. A first connecting part that is movably supported;
The second support portion rotates the power unit with respect to the right side frame so that the center of rotation about the vehicle longitudinal axis is positioned between the power unit and the right side frame in the vehicle width direction. It has the 2nd connection part supported so that movement is possible.

  According to the present invention, the vertical displacement difference between the left side frame and the right side frame that occurs when the frame is twisted is detected by the first and second connecting portions that rotatably support the power unit with respect to the left and right side frames. It is possible to reduce the couple of force applied to the mount portion (support structure portion) of the power unit due to escape and frame twist. As a result, it is not necessary to provide a support cross member between the side frames, the plate thickness of the side frame and the support structure portion can be reduced, and a lightweight structure between the body frame and the mount portion of the power unit can be achieved.

  Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

1 is a side view of a dump truck according to a first embodiment of the present invention. It is a top view which shows arrangement | positioning of the power unit of the dump truck shown in FIG. It is a perspective view which shows the outline of the principal part of the flame | frame of the dump truck shown in FIG. It is the schematic which shows the support structure of the power unit front side in 1st Example. It is the schematic which shows the support structure of the power unit rear side in 1st Example. It is the schematic which shows the frame twist behavior in the support structure of the power unit rear side in 1st Example. It is a figure which shows the components structure of the support structure of the power unit rear side in 1st Example. It is the schematic which shows the example which does not use a pin connection support structure for the support structure of a power unit rear side. It is the schematic which shows the frame twist behavior in the example which does not use a pin connection support structure for the support structure of a power unit rear side. It is the schematic which shows the support structure of the power unit rear side in 2nd Example. It is the schematic which shows the frame twist behavior in the support structure of the power unit rear side in 2nd Example. It is a figure which shows the components structure of the support structure of the power unit rear side in 2nd Example. It is the schematic which shows an example of the support structure of the power unit rear side in 3rd Example. It is the schematic which shows an example of the support structure of the power unit rear side in 3rd Example. It is the schematic which shows an example of the support structure of the power unit front side in 4th Example. It is the schematic which shows an example of the support structure of the power unit front side in 4th Example. It is the schematic (top view) which shows the support structure of the power unit in 5th Example. It is the schematic (top view) which shows the support structure of the power unit in 6th Example.

  Hereinafter, an embodiment according to the present invention will be described with reference to the drawings. In the drawings, “front”, “rear”, “right”, “left”, “upper” and “lower” are appropriately described. In the following description, each direction in the front and rear, left and right, and up and down, or a position in each direction is defined based on these front and rear, left and right, and up and down directions. Moreover, in the following description, about a left-right symmetric structure, one structure is demonstrated among the structures provided in right and left. In this case, the configuration omitted in the description has the same configuration as that described in the description, and “right” may be replaced with “left” or “left” may be replaced with “right”.

  In this embodiment, an example of a power unit support structure that reduces the load on the connecting portion between the side frame and the mount bracket when the frame is twisted will be described. FIG. 1 is a side view of a dump truck according to the present embodiment.

  A dump truck 1 according to this embodiment includes a body frame 2, a pair of front wheels 3, a pair of rear wheels 4, and a loading platform 5. The pair of front wheels 3 are rotatably attached to the left and right ends of the front portion of the body frame 2. The pair of rear wheels 4 is composed of a double tire on one side, and is rotatably attached to the left and right ends of the rear portion of the body frame 2. Furthermore, the loading platform 5 is a portion on which a transport object such as earth and sand or crushed stone is loaded, and is mounted on the vehicle body frame 2 so as to be able to undulate.

  The dump truck 1 of the present embodiment is an electrically driven dump truck. The rear wheel 4 is a driving wheel, and includes a traveling motor 8 that drives the rear wheel 4. In FIG. 1, a power unit 11 (engine 12, alternator 13, and pump 14) that generates electric power for driving the traveling motor 8 is indicated by a dotted line.

  FIG. 2 is a top view showing the arrangement of the power units of the dump truck shown in FIG. FIG. 3 is a perspective view schematically showing the main part of the frame of the dump truck shown in FIG.

  The power unit 11 includes an engine 12, an alternator 13, and a pump 14, and is disposed in the center in the width direction of the frame 2 near the front wheels 3 (3a, 3b). The power unit 11 is supported between a pair of left and right side frames 2b and 2e extending in the longitudinal direction of the vehicle body with an interval in the vehicle width direction (left and right direction). The power unit 11 is connected to the frame 2 at a total of three locations, one on the front side connecting portion 23 on the front side and two on the rear side connecting portions 41 and 42 on the rear side. On the front side, a front mounting bracket 22 (see FIG. 4) is bridged between a pair of left and right front pedestals 21 a and 21 b provided on the upper left plate 2 a and the upper right plate 2 d of the frame 2, and the front connection bracket 22 is connected to the center of the front mounting bracket 22. The unit 23 is connected to the power unit 11 using the part 23.

  The front pedestals 21a and 21b, the front mount bracket 22, and the front connection portion 23 constitute a front support portion that supports the power unit 11 on the left and right side frames 2b and 2e on the front side in the vehicle longitudinal direction. The front mount bracket 22 and a ball bearing (first bearing) to be described later are a third support portion that supports the power unit 11 on the side frames 2L and 2R with respect to a first support portion and a second support portion to be described later. Configure.

  On the rear side, a pair of left and right rear mounting brackets 31 and 32 (see FIG. 5A) provided on the left inner plate 2b (see FIG. 5A) and the right inner plate 2e of the frame 2 are connected to the rear connecting portions 41 and 42, respectively. (Refer FIG. 5A) The power unit 11 is connected. The rear mount bracket 32 and the rear connection part 42 constitute a first support part that supports the power unit 11 to the left side frame 2L. The rear mount bracket 31 and the rear connection portion 41 constitute a second support portion that supports the power unit 11 on the right side frame 2R. In this embodiment, the first support portion and the second support portion constitute a rear support portion that supports the power unit 13 on the rear side in the longitudinal direction of the vehicle body.

  One traveling motor 8 is provided for each of the left and right rear wheels. The left rear wheel 4a is driven by the left traveling motor 8a, and the right rear wheel 4b is driven by the right traveling motor 8b. The power unit 11 drives the alternator 13 with the engine 12 to generate electric power. The left traveling motor 8a and the right traveling motor 8b are driven by the supply of electric power generated by the power unit 11.

  FIG. 4 is a schematic diagram showing a support structure on the front side of the power unit in the present embodiment. FIG. 4 is a view as seen from the front side to the rear side of the vehicle body.

The left side frame 2L includes an upper left plate 2a, a left inner plate 2b, and a left outer plate 2c, and the upper left plate 2a is provided above the left inner plate 2b and the left outer plate 2c. The right side frame 2R includes an upper right plate 2d, a right inner plate 2e, and a right outer plate 2f, and the upper right plate 2d is provided above the right inner plate 2e and the right outer plate 2f. The left front pedestal 21a is provided on the upper left plate 2a,
The right front pedestal 21b is provided on the upper right plate 2d.

  The front pedestals 21a and 21b and the front mounting bracket 22 are connected using a bush 24, a bolt 25, a nut 26, and a receiving plate 27. Further, a ball bearing 23a is used for the front side connecting portion 23 that connects the front side mounting bracket 22 and the power unit 11, and the power unit 11 is free to rotate around the front and rear direction axis around the front side connecting portion 23. The vehicle body longitudinal direction axis is an axis parallel to the horizontal plane and along the longitudinal direction of the vehicle body when the dump truck 1 is placed on the horizontal plane.

  FIG. 5A is a schematic diagram showing a support structure on the rear side of the power unit in the present embodiment. FIG. 5B is a schematic diagram illustrating a frame twisting behavior in the support structure on the rear side of the power unit in the present embodiment. Moreover, FIG. 6 is a figure which shows the components structure of the support structure of the power unit rear side in a present Example. FIG. 6 shows the right support structure. Since the support structure is bilaterally symmetrical, only the right side will be described as an example here, and the description on the left side will be omitted.

  A right rear mounting bracket 31 is installed on the right inner plate 2 e of the frame 2. The right rear mounting bracket 31 includes a contact plate 31a, a side plate 31b, and a bottom plate 31c, and the right inner plate 2e of the frame 2 and the contact plate 31a are joined in parallel. A side plate 31b is joined to both end portions in the front-rear direction of the plate 31a, and a bottom plate 31c is joined to the side plate 31b. The side plate 31b is perpendicular to the contact plate 31a. The bottom plate 31c is perpendicular to the contact plate 31a and the side plate 31b. The bottom plate 31c is provided with a plurality of drill holes 31d for connecting to a right rear side connecting portion 41, which will be described later. Here, the abutting plate 31a may be composed of a plurality of divided plates instead of a single plate as shown in the figure. Alternatively, the abutment plate 31a may be omitted, and the side plate 31b may be directly joined to the right inner plate 2e of the frame 2.

  On the other hand, a right rear connecting portion 41 is attached to the alternator 13 of the power unit 11. The right rear connecting portion 41 includes an alternator bracket 41a, a pin bracket A41b, a pin bracket B41c, a connecting pin 41d, and a pin bracket receiving plate 41e. The alternator 13 and the alternator bracket 41a are joined, and the pin bracket A41b is joined to both ends of the alternator bracket 41a in the front-rear direction. Further, pin brackets B41c are joined to both end portions of the pin bracket receiving plate 41e in the front-rear direction, and the pin bracket A41b and the pin bracket B41c are connected by a connecting pin 41d. Accordingly, the rotation of the pin bracket A41b and the pin bracket B41c around the vehicle body longitudinal axis about the connecting pin 41d is free. Further, the pin bracket receiving plate 41e is provided with a plurality of drill holes 41f for connecting to the rear mount bracket 31.

  The right rear side mounting bracket 31 and the right rear side connecting portion 41 are connected using a bush 24, a bolt 25, a nut 26, and a receiving plate 27.

  As shown in FIG. 5B, when the frame 2 is twisted, the inner plates 2b and 2e of the left and right frames 2 are tilted from their original positions, and the left and right rear mounting bracket bottom plates installed on the inner plates 2b and 2e. 31c and 32c are not located in the same plane as indicated by the dotted lines in the figure. The two plane displacements 33 of the rear mounting bracket bottom plates 31c and 32c are released by the rotation of the pin connecting portions of the left and right rear connecting portions 41 and 42 and the bush 24.

  That is, in the present embodiment, the first support portion (the rear mount bracket 32 and the rear connection portion 42) is configured so that the power unit 11 is rotated around the vehicle body longitudinal axis (the connection pin) with respect to the left side frame 2L. 42d) has the 1st connection part 42 supported so that rotation is possible so that it may be located between the power unit 11 and the left side frame 2L in the vehicle width direction. The second support portion (the rear mount bracket 31 and the rear connection portion 41) is configured such that the rotation center (the connection pin 41d) around the vehicle longitudinal axis is the vehicle width with respect to the right side frame 2R. It has the 2nd connection part 41 supported so that rotation is possible so that it may be located between the power unit 11 and the right side frame 2R in a direction.

  For comparison, FIGS. 7A and 7B show an example in which no pin connection support structure is used on the rear side of the power unit. FIG. 7A is a schematic diagram illustrating an example in which a pin connection support structure is not used for the support structure on the rear side of the power unit. FIG. 7B is a schematic diagram showing a frame twisting behavior in an example in which the pin connection support structure is not used for the support structure on the rear side of the power unit.

  The rear mount brackets 31 and 32 installed on the frame 2 are the same as the structure of the present embodiment, but the left and right rear connection portions 101 and 102 are not pin connection structures but junction structures. Since the structure is bilaterally symmetrical, the right side will be described as an example here. In this comparative example, the alternator 13 and the alternator bracket 101a are joined, and the side plates 101b are joined to both ends in the front-rear direction of the alternator bracket 101a. Further, a receiving plate 101c is joined to the side plate 101b. The receiving plate 101c is provided with a plurality of drill holes 101d for connecting to the rear mounting bracket 31. The right rear side mounting bracket 31 and the right rear side connecting portion 101 are connected using a bush 24, a bolt 25, a nut 26, and a receiving plate 27.

  As shown in FIG. 7B, when the frame 2 is twisted, the inner plates 2b and 2e of the left and right frames 2 are inclined from their original positions. Since the rear connecting portions 101 and 102 do not have a pin connecting structure, the left and right rear mounting bracket bottom plates 31c and 32c installed on the inner plates 2b and 2e have a large displacement 33 as shown in FIG. I can't take it.

  While traveling on a flat road surface, the displacement deviation 33 is not so large, and the deformation can be absorbed by the bush 24 provided between the right rear mounting bracket 31 and the right rear connecting portion 101. However, when traveling on a road surface with severe road surface irregularities, the bush 24 alone cannot absorb a large displacement difference due to the torsion of the frame 2, and a large load is applied to the connection portion between the frame 2 and the alternator 13. In particular, a portion where stress is structurally concentrated, for example, a joint portion (A portion) between the inner plates 2b and 2e of the frame 2 and the rear mounting bracket abutting plates 31a and 32a, an abutting plate 31a of the rear mounting bracket, A high load is applied to the joint portion (B portion) between 32a and the side plates 31b and 32b.

  On the other hand, in the present embodiment, the left and right rear connection portions 41 and 42 have a pin connection structure, so that even when the frame 2 is largely twisted, the torsional deformation of the frame 2 is caused by the rotational deformation of the pin connection portion. It is possible to prevent a large load from being applied to the joining portion connecting the frame 2 and the alternator 13 by escaping.

  As described above, the support cross member provided between the inner plates 2b and 2e of the left and right frames 2 is not used, and the thickness of the frame constituent member can be reduced by reducing the load at the connecting portion between the frame 2 and the power unit 11. . Thereby, the lightweight structure of a vehicle body can be achieved and conveyance efficiency improvement can be implement | achieved.

  In the present embodiment, in consideration of the case where the power unit 11 is assembled to the frame 2 from above, the pin bracket A41b, the pin bracket B41c, and the connecting pin 41d are positioned above the bottom plate 31c. . For this reason, it exists in the tendency for the attachment position of the alternator 13 to become high. However, as shown in FIG. 1, the alternator 13 is arranged on the lower side of the loading platform 5, and avoids interference with the loading platform 5, so it cannot be arranged higher. For this purpose, in this embodiment, the side plate 31b is extended downward with respect to the central portion in the vertical direction (height direction) of the inner plate 2e and the contact plate 31a so that the position of the alternator 13 is lowered. .

  In this embodiment, an example of a power unit support structure in which the pin connecting portion is located below the alternator bracket bottom plate will be described. FIG. 8A is a schematic view showing a support structure on the rear side of the power unit in the present embodiment. FIG. 8B is a schematic diagram showing the frame twisting behavior in the support structure on the rear side of the power unit in the present embodiment. FIG. 9 is a component configuration diagram of the support structure (right side) on the rear side of the power unit. Since the structure is bilaterally symmetrical, the right side will be described as an example here.

  A right rear mounting bracket 51 is installed on the right inner plate 2 e of the frame 2. The right rear mounting bracket 51 includes a contact plate 51a, a side plate 51b, and a bottom plate 51c. The right inner plate 2e of the frame 2 and the contact plate 51a are joined in parallel. A side plate 51b is joined to both ends of the abutting plate 51a in the front-rear direction, and a bottom plate 51c is joined to the side plate 51b. The side plate 51b is perpendicular to the contact plate 51a. The bottom plate 51c is perpendicular to the contact plate 51a and the side plate 51b. In addition, the bottom plate 51c is provided with a plurality of drill holes 51d and a plurality of slits 51e for connecting to a right rear side connecting portion 61 described later. Here, the abutment plate 51a may be configured by using a plurality of divided plates instead of a single plate as shown in the figure. Alternatively, the abutment plate 51 a may be omitted, and the side plate 51 b may be directly joined to the right inner plate 2 e of the frame 2.

  On the other hand, a right rear connecting portion 61 is attached to the alternator 13 of the power unit 11. The right rear connecting portion 61 includes an alternator bracket 61a, a pin bracket A61b, a pin bracket B61c, a connecting pin 61d, and a pin bracket receiving plate 61e. The alternator 13 and the alternator bracket 61a are joined, and the pin bracket A61b is joined to both ends of the alternator bracket 61a in the front-rear direction. Further, a pin bracket B61c is joined to the lower surface side of both ends in the front-rear direction of the pin bracket receiving plate 61e, and the pin bracket A61b and the pin bracket B61c are connected by a connecting pin 61d. Accordingly, the rotation of the pin bracket A61b and the pin bracket B61c around the vehicle body longitudinal axis about the connecting pin 61d is free. The pin bracket receiving plate 61e is provided with a plurality of drill holes 61f for connecting to the rear mounting bracket 51.

  The right rear side mounting bracket 51 and the right rear side connecting portion 61 are connected using a bush 24, a bolt 25, a nut 26, and a receiving plate 27.

  Unlike the first embodiment, the rear mounting bracket bottom plate 51c is located between the alternator bracket 61a and the pin bracket receiving plate 61e of the right rear connecting portion, and the alternator 13 is interposed via the rear connecting portions 61 and 62. It is in a suspended state.

  However, as in the first embodiment, the left and right rear side connecting portions 61 and 62 have a pin connection structure, so that even when a large twist occurs in the frame 2, the rotation of the pin connection portion causes the frame 2 to move. It is possible to prevent torsional deformation and to prevent a large load from being applied to the joint portion connecting the frame 2 and the alternator 13.

  In the present embodiment, the rear mounting bracket 52 and the rear connecting portion 52 constitute a first support portion that supports the power unit 11 on the left side frame 2L. The rear mount bracket 51 and the rear connection portion 61 constitute a second support portion that supports the power unit 11 on the right side frame 2R. In this embodiment, the first support portion and the second support portion constitute a rear support portion that supports the power unit 13 on the rear side in the vehicle longitudinal direction.

  Also in the present embodiment, as in the first embodiment, the first support portion (the rear mounting bracket 52 and the rear connecting portion 62) is arranged around the vehicle longitudinal axis with respect to the left side frame 2L. Has a first connecting portion 62 that is rotatably supported so that the center of rotation (the connecting pin 62d) is positioned between the power unit 11 and the left side frame 2L in the vehicle width direction. The second support portion (rear side mounting bracket 51 and rear side connecting portion 61) is such that the rotation center (the connecting pin 61d) around the vehicle body longitudinal axis is relative to the right side frame 2R with respect to the power unit 11. It has the 2nd connection part 61 supported so that rotation is possible so that it may be located between the power unit 11 and the right side frame 2R in a direction.

  In this embodiment, the connecting pin 61d is positioned below the bottom plate 51c and the pin bracket receiving plate 61e, and the rotation center of the pin bracket A61b and the pin bracket B61c is below the bottom plate 51c and the pin bracket receiving plate 61e. Is located. Thereby, in the present embodiment, the alternator 13 can be arranged lower than the first embodiment. For this reason, in this embodiment, the rear mount bracket bottom plate 51c can be disposed at the center in the vertical direction (height direction) of the side plate 51b, and the force applied to the side plate 51b can be reduced. Further, since the center of gravity of the alternator 13 is lower than the mounting position, the alternator 13 is stabilized. Thereby, the support structure of the power unit 11 can be reduced in size and weight.

  In this embodiment, an example of a power unit support structure that not only reduces the load on the connecting portion between the side frame and the mount bracket when the frame is twisted but also limits the amount of movement of the power unit will be described. 10A and 10B are schematic views illustrating an example of a support structure on the rear side of the power unit in the present embodiment.

  A secondary spring 71 (FIG. 10A) or a direct acting piston type hydraulic damper 74 (FIG. 10B) was installed in the power unit support structure of this example. In the secondary spring 71, the spring connecting portion 72 is installed in the alternator 13, the spring connecting portion 73 is installed in the rear mount bracket side plates 31 b and 32 b, and the two spring connecting portions 72 and 73 are connected by the secondary spring 71. In the direct acting piston type hydraulic damper 74, a damper connecting portion 75 is installed in the alternator 13, a damper connecting portion 76 is installed in the rear mounting bracket side plates 31b, 32b, and a direct acting piston type hydraulic pressure is provided between both damper connecting portions 75 and 76. The dampers 74 were connected. Thereby, the moving amount | distance of the left-right direction of the power unit 11 at the time of a frame twist deformation | transformation can be restrict | limited. Further, the direct acting piston hydraulic damper 74 can control the pendulum vibration in the left-right direction of the power unit 11.

  The spring connecting portion 72 or the damper connecting portion 75 installed on the alternator 13 includes the alternator brackets 41a and 42a, the pin brackets A41b and 42b, the pin brackets B41c and 42c, or the connecting pins 41d and 42d of the rear connecting portions 41 and 42. It may be installed in. In addition, the spring connecting portion 73 or the damper connecting portion 76 installed on the rear mounting bracket side plates 31b and 32b is the abutting plates 31a and 32a and the bottom plates 31c and 32c, which are components of the rear mounting bracket other than the side plates 31b and 32b. Furthermore, you may install in flame | frame 2e, 2b.

  In this embodiment, the secondary spring 71 or the direct acting piston type hydraulic damper 74 is installed in the power unit support structure of the first embodiment. However, the secondary spring 71 or the A dynamic piston type hydraulic damper 74 may be installed.

  In this embodiment, an example of a support structure on the front side of the power unit that further reduces the load on the connecting portion between the side frame and the mount bracket when the frame is excessively twisted will be described. 11A and 11B are schematic views illustrating an example of a support structure on the front side of the power unit in the present embodiment.

  As shown in FIG. 11A, in the first to third embodiments, a ball bearing 23a is used for the front connecting portion 23 that connects the upper front mounting bracket 22b and the power unit 11. Thereby, the rotation around the vehicle body longitudinal axis (X axis) in the power unit 11 around the front connection portion 23 is free. The ball bearing 23a is provided on the mount bracket 22 and constitutes a first bearing that supports the power unit 11 so as to be rotatable around a vehicle body longitudinal axis.

  In this embodiment, as shown in FIG. 11B, the upper front mounting bracket 22b is divided into two brackets 22c and 22d. The bracket 22d includes a front side connecting portion 23 that is connected to the power unit 11, and further includes a threaded pin 28 that is connected to the bracket 22c. The threaded pin 28 is inserted into a connecting portion 29 provided on the bracket 22c, and the lower side is fixed with a nut 30. The connecting portion 29 is a ball bearing, and by arranging the axial direction of the threaded pin 28 in the vertical direction of the vehicle body (Y-axis direction), the bracket 22d can freely rotate around the vertical axis of the vehicle body (Y-axis) on the bracket 22c. Become. The connecting portion 29 constitutes a second bearing that supports the ball bearing 23a (first bearing) so as to be rotatable about the vertical axis.

  As a result, the power unit 11 is free to rotate not only around the vehicle longitudinal axis (X axis) but also around the vehicle vertical axis (Y axis) with respect to the front mounting bracket 22, and the left and right sides of the power unit 11 when the frame is twisted. The load applied to the connecting portion between the power unit 11 and the frame 2 with respect to the movement in the direction can be further reduced.

  In this embodiment, another example of the power unit support structure will be described. FIG. 12 is a schematic view (top view) showing the support structure of the power unit in the present embodiment.

  The front support structure of the power unit 11 is not the structure shown in FIG. 4 or 11B, but the same as the rear support structure shown in the first to third embodiments. That is, the rear support structure shown in FIG. 5A, FIG. 8A, or FIG. 10 is also applied to the front side. By using the power unit 11 as a four-point support instead of a three-point support, a more stable support structure is obtained.

  In this embodiment, another example of the power unit support structure will be described. FIG. 13 is a schematic view (top view) showing the support structure of the power unit in the present embodiment.

  The front side support structure and the rear side support structure of the power unit 11 shown in Examples 1 to 3 are interchanged, and the front side is supported at two points and the rear side is supported at one point. The support structure of the present embodiment may be configured by arranging components other than the power unit 11 mounted on the frame 2.

  In each of the above-described embodiments, the support structure for the power unit 11 according to the present invention is applied to an electrically driven dump truck. Since the electric drive type dump truck is not connected to the axle of the drive wheel 4, the electric drive type dump truck is suitable for providing the rotation mechanism of each embodiment described above on the support structure of the power unit 11. Each embodiment also applies to a mechanical dump truck that connects the drive shaft of the power unit 11 to the axle of the drive wheel 4 by connecting the drive shaft of the power unit 11 and the axle of the drive wheel 4 via a universal joint. The support structure can be applied.

  Further, in the above-described embodiment, the pin coupling in which the pin brackets A41b and 61b and the pin brackets B41c and 61c are coupled by the coupling pins 41d and 61d can be replaced with, for example, coupling by a ball joint. The pin brackets A41b and 61b, the pin brackets B41c and 61c, and the connection pins 41d and 61d, or the ball joint described above, support portions (connection portions) that support the power unit 11 so as to be rotatable with respect to the side rails 2L and 2R. Configure.

  According to each of the above-described embodiments, the vertical displacement difference between the left and right mounting bracket portions generated when the frame is twisted is released by the pin connecting portion, and the even load applied to the connecting portion between the side frame and the mounting bracket portion due to the frame twisting. The force can be reduced. Rather than providing a support cross member between the side frames 2L and 2R to increase the frame rigidity, the pin connection structure eliminates deformation and reduces the load on the connection part, eliminating the need for a support cross member that increases weight. Further, it is possible to reduce the thickness of the side frame and the mounting bracket portion, and to achieve a lightweight structure. In mining dump trucks, the total weight including the weight of the vehicle body and the load weight is regulated by the tire load capacity. By reducing the vehicle body weight, the maximum load capacity can be increased and transportation efficiency can be improved. Is possible.

  In addition, this invention is not limited to each above-mentioned Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Dump truck, 2 ... Body frame, 2L ... Left side frame, 2R ... Right side frame, 11 ... Power unit, 21a ... Left front side base, 21b ... Right front side base, 22 ... Front side mounting bracket, 23 ... Front side connection part, 23a ... Ball bearing, 31 ... Right rear mounting bracket, 32 ... Left rear mounting bracket, 41 ... Right rear coupling portion, 41d ... Right rear pin bracket coupling pin, 42 ... Left rear coupling portion, 42d ... Left Rear side pin bracket connecting pin, 51 ... Right rear side mounting bracket, 52 ... Left rear side mounting bracket, 61 ... Right rear side connecting portion, 61d ... Right rear side pin bracket connecting pin, 62 ... Left rear side connecting portion, 62d ... left rear pin bracket connecting pin, 71 ... secondary spring, 74 ... direct acting piston type hydraulic damper.

Claims (5)

In a dump truck provided with a pair of left and right side frames extending in the longitudinal direction of the vehicle body with an interval in the vehicle width direction, and a power unit supported between the pair of left and right side frames,
The support structure for supporting the power unit on the pair of left and right side frames includes a first support part for supporting the power unit on a left side frame, and a second support part for supporting the power unit on a right side frame,
The first support portion rotates the power unit with respect to the left side frame so that the center of rotation about the vehicle longitudinal axis is positioned between the power unit and the left side frame in the vehicle width direction. A first connecting part that is movably supported;
The second support portion rotates the power unit with respect to the right side frame so that the center of rotation about the vehicle longitudinal axis is positioned between the power unit and the right side frame in the vehicle width direction. A dump truck having a second connecting portion that is movably supported. The dump truck according to claim 1,
The support structure includes a front support portion that supports the power unit on the front side in the vehicle longitudinal direction, and a rear support portion that supports the power unit on the rear side in the vehicle longitudinal direction,
One of the front support part and the rear support part is configured by the first support part and the second support part, and the other is straddled between the left side frame and the right side frame. A dump truck comprising: a mount bracket provided; and a third support portion provided on the mount bracket and having a first bearing that rotatably supports the power unit about a vehicle body longitudinal axis. . The dump truck according to claim 2,
2. A dump truck according to claim 1, wherein a second bearing that supports the first bearing so as to be rotatable about a vertical axis is provided on the third support portion. The dump truck according to claim 1,
The support structure includes a front support portion that supports the power unit on the front side in the vehicle longitudinal direction, and a rear support portion that supports the power unit on the rear side in the vehicle longitudinal direction,
The front support portion is composed of the first support portion and the second support portion,
The dump truck according to claim 1, wherein the rear support portion is constituted by the first support portion and the second support portion. The dump truck according to claim 1,
The first support portion includes a damper that limits a movement amount of the power unit in the vehicle width direction between the left side rail side and the power unit side,
The dump truck according to claim 2, wherein the second support portion includes a damper that limits a movement amount of the power unit in a vehicle width direction between the right side rail side and the power unit side.

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