Support structure of the vehicle cab, and the vehicle

Abstract

To provide a support structure for a vehicle cab that can maintain the cab's connection to the vehicle frame during appropriate frontal collision tests of a cab-over type vehicle. [Solution] The support structure for the vehicle cab comprises a first bracket fixed to the front of the vehicle frame, a link arm whose front end is rotatably supported relative to the first bracket, a joint portion rotatably supported relative to the rear end of the link arm by an axis along the left-right direction of the vehicle, a fixing portion fixed to the front of the cab positioned above the vehicle frame, and a connecting member. The connecting member is provided on at least one of the lower surface and side surface of the second bracket, and maintains a connected state between the front and rear sides of the crack-prone portion when a load is applied from the front of the vehicle and a crack occurs in the crack-prone portion of the second bracket.

Description

Technical Field

[0001] The present invention relates to a support structure for a cab of a vehicle and a vehicle having the support structure.

Background Art

[0002] For example, Patent Document 1 discloses a support structure for the front portion of a cab of a cab-over type vehicle.

[0003] For example, Non-Patent Document 1 describes the "Concerning the adoption of uniform technical prescriptions for wheeled vehicles, equipment and parts which can be fitted and / or be used on wheeled vehicles and the conditions for reciprocal recognition of approvals granted on the basis of these prescriptions" agreement (January 2, 2012) defined by the United Nations. Non-Patent Document 1 discloses a test method for a frontal collision (Test-A frontal collision test) of a cab-over type vehicle.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Non-Patent Documents

[0005]

Non-Patent Document 1

Summary of the Invention

[0006] For example, in the Test-A frontal crash test disclosed in Non-Patent Document 1, it is required that the cab remain connected to the vehicle frame.

[0007] The present invention aims to provide a vehicle cab support structure and a vehicle that can maintain the cab connected to the vehicle frame when a suitable frontal collision test is performed on a cab-over type vehicle. [Means for solving the problem]

[0008] A support structure for a vehicle cab according to one aspect of the present invention comprises: a first bracket fixed to the front of a vehicle frame extending in the longitudinal direction of the vehicle; a link arm having a front end and a rear end located at a position extending rearward from the front end, the front end of which is rotatably supported relative to the first bracket by a first axis along the left-right direction of the vehicle; a joint portion rotatably supported relative to the rear end of the link arm by a second axis along the left-right direction of the vehicle; and a fixing portion fixed to the front of a cab positioned above the vehicle frame, the fixing portion having a crack-inducing portion in which a crack is expected to occur due to a rotational moment with the second axis as a fulcrum when a load is applied from the front side of the vehicle; and a connecting member provided on at least one of the lower surface and side surface of the second bracket, which maintains the front and rear sides of the crack-inducing portion connected when a load is applied from the front side of the vehicle and the crack occurs in the crack-inducing portion of the second bracket. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a support structure for the cab of a vehicle, and a vehicle, that can maintain the state in which the cab is connected to the vehicle frame when a suitable frontal collision test is performed on a cab-over type vehicle. [Brief explanation of the drawing]

[0010] [Figure 1] (A) is a portion of the left side view showing the vehicle and the pendulum-shaped impactor used in a frontal collision test of the vehicle, and (B) is a schematic front view of the pendulum-shaped impactor shown in (A). [Figure 2] An enlarged view of the support structure, seen from the same direction as Figure 1(A), showing how the cab is supported by the vehicle's frame at the front left side of the vehicle. [Figure 3] A schematic perspective view of the second bracket and connecting member of the support structure in Figure 2, viewed from the lower left front. [Figure 4] Figure 3 shows a schematic diagram of the second bracket and connecting member of the support structure, viewed from the left and from below, side by side. [Figure 5] A schematic diagram showing an example of a crack occurring in the second bracket of the support structure during the test shown in Figure 1. [Figure 6] A bottom view of the second bracket and connecting member in Figure 5. [Modes for carrying out the invention]

[0011] The support structure 16 of the cab 14 of the vehicle 10 according to the present invention will be described below with reference to the drawings.

[0012] In this embodiment, each direction is based on the vehicle 10. For example, "up" means above the vehicle 10, and "forward" means in front of the vehicle 10.

[0013] Figure 1(A) schematically shows a portion of the left side view of a so-called cab-over type vehicle 10. Also shown in Figure 1(A) is the pendulum-shaped impactor P of the Test-A frontal crash test (hereinafter mainly referred to as the test) of the cab-over type vehicle 10, as described in the United Nations Agreement concerning "Concerning the adoption of uniform technical prescriptions for wheeled vehicles, equipment and parts which can be fitted and / or be used on wheeled vehicles and the conditions for reciprocal recognition of approvals granted on the basis of these prescriptions". Figure 1(B) is a schematic front view of the pendulum-shaped impactor P shown in Figure 1(A).

[0014] Figure 2 shows an enlarged view of the support structure 16 that supports the cab 14 at the left front of the vehicle 10 relative to the body frame 12, viewed from the same direction as in Figure 1(A). That is, the left side in Figure 2 is the front of the vehicle 10, and the top side is the top of the vehicle 10. Figure 3 shows a schematic perspective view of the second bracket 26 and connecting member 28 of the support structure 16 in Figure 2, viewed from the lower left front. Figure 4 shows a schematic view of the second bracket 26 and connecting member 28 of the support structure 16 shown in Figure 3, viewed from the left and from below, side by side. Reference numeral B0 indicates a virtual plane of the same plane in the vertical and horizontal directions of the second bracket 26 and connecting member 28.

[0015] As shown in Figure 1, the vehicle 10 has a body frame (chassis) 12, a cab 14, and a pair of support structures 16 that support the cab 14 at the front of the cab 14 relative to the body frame 12. Generally, the vehicle 10 has a pair of support structures that support the cab 14 at the rear of the cab 14 relative to the body frame 12, but a description of this will be omitted.

[0016] Hereinafter, the support structure 16 will be described as supporting the cab 14 with respect to the vehicle body frame 12 at the left front portion of the vehicle 10. Although not shown, the vehicle 10 also has a support structure 16 that supports the cab 14 with respect to the vehicle body frame 12 at the right front portion of the vehicle 10. It is preferable that these pair of left and right support structures 16 are symmetric. For this reason, it is preferable that the support structure 16 is provided so as to be spaced apart in the left-right direction with respect to the front portion of the vehicle body frame 12 and the front portion of the cab 14.

[0017] As shown in FIG. 2, the support structure 16 includes a first bracket 22, a link arm 24, a second bracket 26, a connecting member 28, a shock absorber 30, a spring 32, and a cushion rubber 34.

[0018] The first bracket 22, the link arm 24, and the second bracket 26 are formed as, for example, a cast structure. As an example of the material of the casting, cast iron or cast steel can be used. Also, as an example of the material of the casting, an aluminum alloy or the like can be used as the material.

[0019] The lower end portion 22a of the first bracket 22 is fixed to the front portion of the vehicle body frame 12 whose longitudinal direction extends in the longitudinal direction of the vehicle 10. In the present embodiment, the first bracket 22 extends upward from the front portion of the vehicle body frame 12.

[0020] The link arm 24 has a front end 24a, a rear end 24b, and an intermediate body 24c. The link arm 24 extends rearward from the front end 24a to the rear end 24b. The front end 24a of the link arm 24 is rotatably supported by a first shaft 18a that runs along the left-right direction of the vehicle 10 relative to the upper end 22b of the first bracket 22. The front end 24a of the link arm 24 supports the lower end of the shock absorber 30. The rear end 24b of the link arm 24 is rotatably supported by a second shaft 18b that runs along the left-right direction of the vehicle 10 relative to the second bracket 26. The intermediate body 24c of the link arm 24 is provided between the front end 24a and the rear end 24b. The upper surface of the intermediate body 24c has a base 24d made of, for example, rubber, for the lower ends of the spring 32 and cushion rubber 34.

[0021] As shown in Figures 2 to 4, the second bracket 26 integrally includes a joint portion 42 and a fixing portion 44.

[0022] The joint portion 42 of the second bracket 26 is rotatably supported by a second shaft 18b that runs along the left-right direction of the vehicle 10, relative to the rear end 24b of the link arm 24.

[0023] The fixing portion 44 is fixed to the lower front part of the cab 14, which is positioned above the vehicle frame 12. The fixing portion 44 is fixed to the cab 14 above the link arm 24, in a position that extends forward of the joint portion 42 of the second bracket 26. The fixing portion 44 is fixed to the cab 14 with bolts 46 at multiple locations on the lower and left side (outer side in the vehicle width direction) of the second bracket 26. In this embodiment, the fixing portion 44 is fixed to the cab 14 with bolts 46 at a total of seven locations: three on the left side and four on the lower side of the second bracket 26. It is preferable that the same bolts 46 are used at all seven locations. In this embodiment, the positions of the three bolts 46 on the left side of the second bracket 26 are each located close to the upper end of the second bracket 26.

[0024] The fixed portion 44 comprises a rear portion 52 provided integrally with the joint portion 42 on the upper side of the joint portion 42 and fixed to the cab 14, a front portion 54 provided forward of the rear portion 52, spaced apart above the first bracket 22 and above the link arm 24, fixed to the cab 14, and an intermediate portion 56 provided between the rear portion 52 and the front portion 54 and fixed to the cab 14. In this embodiment, the boundary between the rear portion 52 and the intermediate portion 56 is assumed to be a virtual plane at the position indicated by the dashed line indicated by reference numeral B1 in Figure 2. Also, in this embodiment, the boundary between the intermediate portion 56 and the front portion 54 is assumed to be a virtual plane at the position indicated by the dashed line indicated by reference numeral B2 in Figure 2. The virtual plane is, for example, a plane formed by the vertical and horizontal directions of the vehicle 10.

[0025] The rear section 52 is fixed to the cab 14 with bolts 46 at a total of three points: two from the underside of the second bracket 26 and one from the left side. The front section 54 is fixed to the cab 14 with bolts 46 at a total of three points: two from the underside of the second bracket 26 and one from the left side. The middle section 56 is fixed to the cab 14 with bolts 46 at one point from the left side of the second bracket 26. Therefore, the number of fixing points for the middle section 56 to the cab 14 is fewer than the fixing points for the rear section 52 and the front section 54.

[0026] In the second bracket 26, the rear region 60, where the joint portion 42 and the rear portion 52 of the fixing portion 44 are integrated, has a pair of walls 64 that each form an arc-shaped rib 62 facing forward and downward, as well as a connecting wall 66 that connects the walls 64. Therefore, the rear region 60 of the second bracket 26 is formed to have appropriate strength.

[0027] The front portion 54 includes a support portion 70 that supports the upper end of the shock absorber 30. The support portion 70 extends to the left from the left side. The support portion 70 is not simply a flat plate, but is formed as a combination of multiple surfaces, thereby increasing the strength of the front portion 54. The support portion 70 may also preferably have a curved surface. In this way, the front portion 54 of the second bracket 26 is formed to have appropriate strength.

[0028] The intermediate section 56 has a base 80 on its lower surface that supports the upper ends of the spring 32 and the cushion rubber 34. The surface of the base 80 that supports the cushion rubber 34, for example, is formed to be thinner than the adjacent parts. The base 80 also includes a guide 80a that surrounds the outer circumference of the upper end of the spring 32 in the circumferential direction. In this embodiment, the guide 80a is not formed to cover 360°, but rather to surround, for example, about two-thirds of the outer circumference of the upper end of the spring 32. The front side of the guide 80a is open.

[0029] The wall forming the bolt holes (bolt fixing holes) 46a in the intermediate section 56 is formed thinner than, for example, the wall forming the bolt holes (bolt fixing holes) 46b in the rear section 52 and the front section 54. Therefore, the bolt holes 46a in the intermediate section 56 are formed with lower bending strength than the bolt holes 46b in the rear section 52 and the front section 54. In other words, the bolt holes 46b in the rear section 52 and the front section 54 are formed with higher bending strength than the bolt holes 46a in the intermediate section 56.

[0030] The intermediate section 56 has a crack-inducing section 58 that is intended to generate a crack C when a load is applied from the front side of the vehicle 10 during a head-on collision test of the cab-over type vehicle 10. The crack-inducing section 58 of the intermediate section 56 is a part that is intended to generate a crack C due to a rotational moment with the second shaft 18b as the fulcrum when a load is applied from the front side of the vehicle 10. Preferably, the crack-inducing section 58 is formed to be confined within the intermediate section 56 so that the crack C does not propagate to the rear section 52 and the front section 54.

[0031] In this embodiment, a first boss 92 is provided on the rear portion 52 or boundary B1 of the lower surface of the second bracket 26, for example, on the right side of the lower surface of the second bracket 26, on which a bolt 96 for fixing the connecting member 28 is fastened. Preferably, the first boss 92 is provided on the lower right side of the second bracket 26, far from the bolt hole 46a on the left side of the second bracket 26. Preferably, the central axis of the first boss 92, i.e., the central axis of the bolt 96 fastened to the first boss 92, is located on the rear portion 52 side, not the intermediate portion 56 side. A second boss 94 is provided on the front portion 54 or boundary B2 of the lower surface of the second bracket 26, on which a bolt 96 for fixing the connecting member 28 is fastened. Preferably, the second boss 94 is provided on the lower right side of the second bracket 26, far from the bolt hole 46a on the left side of the second bracket 26. Preferably, the central axis of the second boss 94, i.e., the central axis of the bolt 96 fastened to the second boss 94, is located on the front portion 54 side, not the intermediate portion 56 side. The bosses 92 and 94 are formed, for example, in a cylindrical shape. The region between bosses 92 and 94 is within the range of the intermediate section 56.

[0032] Furthermore, the left side of the second bracket 26 described above can be described as being located on the outer side in the vehicle width direction, and the right side of the second bracket 26 can be described as being located inward from the outer side in the vehicle width direction.

[0033] Of the intermediate section 56, the bolt hole 46a on the left side where the bolt 46 is located can be the starting point of the crack initiation area 58. For example, the left side end of the guide 80a can be the destination of a crack C when it propagates from the bolt hole 46a. As described above, the surface of the base 80 on which the cushion rubber 34 is supported is formed to be thinner than the adjacent parts. Therefore, the surface of the base 80 on which the cushion rubber 34 is supported can be the destination of a crack C when it propagates from the bolt hole 46a or the left side end of the guide 80a. In addition, the right side end of the guide 80a can be the destination of a crack C when it propagates from the bolt hole 46a, the left side end of the guide 80a, or the surface on which the cushion rubber 34 is supported.

[0034] Furthermore, the surface of the base 80 that supports the cushion rubber 34 can be used as the destination for crack C when it propagates from the bolt hole 46a through the portion along the base of the guide 80a.

[0035] Furthermore, if the crack C propagates near bosses 92 and 94, it is conceivable that it would fracture along the base of bosses 92 and 94. However, while crack C may propagate forward on the first boss 92, it is unlikely to propagate backward. Similarly, while crack C may propagate backward on the second boss 94, it is unlikely to propagate forward. For this reason, crack C is most likely to propagate between bosses 92 and 94. This is because the fracture surface of crack C should be a fracture surface that separates bosses 92 and 94, which separate the second bracket 26 in the anterior-posterior direction.

[0036] Although the manner in which crack C propagates is expected to vary widely, the extent of crack C's propagation can be limited to within the intermediate section 56.

[0037] In this embodiment, the connecting member 28 is provided on the lower side of the second bracket 26. The rear end of the connecting member 28 is fixed to the first boss 92 with a bolt 96, and the front end of the connecting member 28 is fixed to the second boss 94 with a bolt 96.

[0038] The connecting member 28 according to this embodiment has a first portion 28a fixed to the first boss 92 with a bolt 96, a second portion 28b fixed to the second boss 94 with a bolt 96, and a third portion 28c between the first portion 28a and the second portion 28b. Between the first portion 28a and the third portion 28c, and between the second portion 28b and the third portion 28c, the third portion 28c is bent so that it is closer to the lower surface of the second bracket 26 than the first portion 28a and the second portion 28b. As a result, when viewed from the left side of the vehicle 10, the connecting member 28 is formed in a hat shape that is convex upward, that is, convex toward the lower surface of the second bracket 26.

[0039] The connecting member 28 is preferably made of a hot-rolled material such as JSH440, a carbon-manganese steel with a tensile strength of 440 MPa or more. An example of the thickness of the connecting member 28 is about 3.2 mm. The length in the front-to-back direction and the width in the left-to-right direction of the connecting member 28 are set as appropriate. Such a hot-rolled connecting member 28 has properties such as being tougher and less prone to fracture compared to a cast structure such as the second bracket 26. Furthermore, when a load is applied from the front side of the vehicle 10, the connecting member 28 can maintain a state in which the front side, i.e., the front part 54, and the rear side, i.e., the rear part 52, of the crack-prone portion 58 of the intermediate portion 56 of the second bracket 26 are connected by a rotational moment with the second shaft 18b as the fulcrum.

[0040] For example, the vehicle 10 may sway when driving depending on the road surface shape. The support structure 16 of the vehicle 10 according to this embodiment includes a plate-shaped connecting member 28 that is long in the front-to-back direction. The connecting member 28 is provided on the lower surface of the second bracket 26. Therefore, the vehicle 10 can use the connecting member 28 as a reinforcing member to prevent lateral swaying of the vehicle 10 when driving. In addition, the connecting member 28 has bent portions between the first portion 28a and the third portion 28c, and between the second portion 28b and the third portion 28c. Therefore, compared to the case where the connecting member 28 is a simple flat plate, twisting of the connecting member 28 can be suppressed, making it easier to prevent lateral swaying of the vehicle 10.

[0041] For example, when the vehicle 10 sways up and down in accordance with the road surface shape, vibrations of the vehicle frame 12 are transmitted to the cab 14 via the support structure 16. These vibrations are reduced by the expansion and contraction of the shock absorber 30, spring 32, and cushion rubber 34.

[0042] Here, we will briefly explain the head-on collision test of the cab-over type vehicle 10 using Figures 1(A) and 1(B).

[0043] The test uses a pendulum-shaped impactor P. The impactor P is made of steel, and its mass is evenly distributed. The mass of the impactor P is 1500 kg or more. The surface of the impactor P is rectangular and flat, with a width b of 2500 mm and a height h of 800 mm. The edges of the impactor P are formed with a radius of curvature of 10 mm ± 5 mm.

[0044] The impactor P assembly is a rigid structure. The impactor P is freely suspended by two beams B that are firmly mounted at a distance f of 1000 mm or more. The length of beam B from the support axis S to the geometric center E of the impactor P is 3500 mm or more.

[0045] The impactor P is positioned vertically as follows: The surface of the impactor P contacts the foremost part of the vehicle 10. The center of gravity of the impactor P is c=50+5 / -0mm below the driver's seat reference point. Its center of gravity lies on the longitudinal central plane of the vehicle 10.

[0046] The impactor P strikes the cab 14 from the front towards the rear. The direction of impact is horizontal and parallel to the longitudinal center plane of the vehicle 10.

[0047] The impact energy of the impactor P on the vehicle 10 is as follows: For Category N1 vehicles 10 and Category N2 vehicles with a total mass of 7.5t or less, it is 29.4kJ. For Category N3 vehicles 10 and Category N2 vehicles with a total mass of 7.5t or more, it is 55kJ.

[0048] Figure 5 shows a schematic diagram illustrating an example of a crack C occurring in the second bracket 26 when the test shown in Figure 1 is performed. Figure 6 shows a bottom view of the second bracket 26 in Figure 5.

[0049] In this embodiment, it is assumed that when the test is performed, neither the vehicle frame 12 nor the first bracket 22 and link arm 24 will be destroyed.

[0050] During the test, the impactor P applies a load to the cab 14 from the front to the rear. At this time, the load of the impactor P acts to push the second bracket 26, which is fixed to the cab 14, backward, as indicated by the symbol F in Figure 5.

[0051] The shock absorber 30 becomes detached from the support portion 70 of the second bracket 26 due to the load on the second bracket 26, which connects to the link arm 24. The spring 32 and cushion rubber 34 also become detached from the base 24d of the link arm 24 and the base 80 of the second bracket 26 due to the load on the second bracket 26.

[0052] At this time, the front end 24a of the link arm 24, which includes the first shaft 18a, attempts to maintain its position relative to the vehicle frame 12, while the rear end 24b, which includes the second shaft 18b, attempts to move rearward relative to the vehicle frame 12. As a result, the link arm 24 is braced in the longitudinal direction indicated by the symbol T. However, the link arm 24 is prevented from breaking by the strength of the link arm 24 itself.

[0053] During the crash test, the load on the second bracket 26 is converted into a rotational moment M with the second shaft 18b, which is the connecting member to the link arm 24, as the fulcrum, and a bending load is applied to the second bracket 26. Then, failure occurs at the weak point of the second bracket 26.

[0054] The front portion 54 of the second bracket 26 has a greater distance from the second shaft 18b, which is a connecting member between the second bracket 26 and the link arm 24, compared to the rear portion 52 and the intermediate portion 56. Therefore, the rotational moment applied to the front portion 54 with the second shaft 18b as the fulcrum is less favorable than the rotational moment applied to the rear portion 52 and the intermediate portion 56. However, the front portion 54 has a support portion 70, etc., and the bolt holes 46b are formed to be thicker than the bolt holes 46a of the intermediate portion 56, making it more resistant to damage than the intermediate portion 56.

[0055] Furthermore, the rear portion 52 of the second bracket 26 has a smaller distance from the second shaft 18b, which is a connecting member between the second bracket 26 and the link arm 24, compared to the front portion 54 and the intermediate portion 56. Therefore, the rotational moment applied to the rear portion 52 with the second shaft 18b as the fulcrum is more favorable than the rotational moment applied to the front portion 54 and the intermediate portion 56. In addition, the rear portion 52 of the second bracket 26 has a structure that is less susceptible to damage than the intermediate portion 56, due to the wall 64 with ribs 62 and the connecting wall 66.

[0056] As a weak point of the second bracket 26, in the support structure 16 according to this embodiment, the bolt hole 46a of the fastening bolt 46 of the intermediate section 56 shown in Figure 5 becomes the starting point for cracking. This is because there is little material around the bolt hole 46a of the fastening bolt 46 of the intermediate section 56, making it susceptible to bending moments. Furthermore, the bolt hole 46a of the fastening bolt 46 of the intermediate section 56 can be made a stable starting point for cracking.

[0057] In this embodiment, of the fastening bolts 46 between the second bracket 26 and the cab 14, the fastening bolts 46 at the front portion 54 maintain their connection to the cab 14. On the other hand, the fastening bolts 46 at the four points in the middle portion 56 and the rear portion 52 break.

[0058] Thus, when using the support structure 16 according to this embodiment, testing reveals that the bolt hole 46a of the fastening bolt 46 in the intermediate section 56 becomes the starting point for the crack C. The crack C then propagates from the bolt hole 46a of the fastening bolt 46, passing through the relatively thin-walled section. The crack C propagates toward the lower surface of the second bracket 26. As shown in Figure 6, the crack C can propagate all the way to the base 80 on the lower surface of the second bracket 26.

[0059] In the support structure 16 of this embodiment, when such a test is performed, the connection between the connecting member 28 and the rear portion 52 of the second bracket 26, and the connection between the connecting member 28 and the front portion 54 are maintained. Furthermore, even if the second bracket 26 is completely separated into the rear portion 52 side and the front portion 54 side by a crack C, the connecting member 28 will only deform and will not break, maintaining the state in which the rear portion 52 and the front portion 54 are connected. Therefore, when the vehicle 10 according to this embodiment is tested, if the support structure 16 is used, even if the second bracket 26 is separated by a crack C, the first bracket 22, link arm 24, the rear portion 52 of the second bracket 26, connecting member 28, and the front portion 54 of the second bracket 26 will not separate, and the connection between the vehicle frame 12 and the cab 14 will be maintained.

[0060] As described above, the connecting member 28 is formed in a hat shape that is convex upwards, i.e., toward the second bracket 26, when viewed from the left side of the vehicle 10. Therefore, when testing is performed, the third portion 28c is more likely to bend toward the lower surface of the second bracket 26 compared to when the entire connecting member 28 is formed as a flat plate. Accordingly, when testing is performed, the direction of deformation of the connecting member 28 in this embodiment can be set to a predetermined direction.

[0061] In this embodiment, an example in which the connecting member 28 is provided on the lower side of the second bracket 26 has been described. The connecting member 28 may also be provided on the side of the second bracket 26, for example, on the outer side in the vehicle width direction. In the example shown in Figure 2, bosses 92 and 94 can be provided on the left side of the second bracket 26 so as to straddle the area where crack C is expected to occur, and the connecting member 28 can be fixed to the bosses 92 and 94 with bolts 96. In this case, it is preferable that the connecting member 28 be formed in a hat shape that is convex toward the side of the second bracket 26. Therefore, when the connecting member 28 is fixed to the bosses 92 and 94 of the second bracket 26, it is preferable that it be formed in a hat shape that is convex toward the second bracket 26. It is also preferable that the connecting member 28 be provided on both the lower side and the left side of the second bracket 26. Therefore, it is preferable that the connecting member 28 be provided on at least one of the lower surface and the side of the second bracket 26.

[0062] In this embodiment, an example has been described in which the United Nations-established frontal collision test for cab-over vehicles (Test-A frontal collision test) is used as the frontal collision test for the vehicle 10. The test is not limited to this, and may also follow ECE regulations or similar tests established by each country. Even when performing such similar tests, if the support structure 16 of the cab 14 according to this embodiment is used, even if the second bracket 26 separates due to crack C, the first bracket 22, link arm 24, rear part 52 of the second bracket 26, connecting member 28, and front part 54 of the second bracket 26 will not separate, and the connection between the vehicle frame 12 and the cab 14 will be maintained.

[0063] In this embodiment, an example in which a rolled metal plate is preferably used as the connecting member 28 has been described. As the connecting member 28, a chain or wire of an appropriate length, formed so as not to break during testing, can be used and fixed to the second bracket 26 in the same way as the metal plate.

[0064] It should be noted that the present invention is not limited to the embodiments described above, and can be modified in various ways during implementation without departing from its essence. Furthermore, each embodiment may be combined as appropriate, and in that case, the combined effects can be obtained. Moreover, the above embodiments include various inventions, and various inventions can be extracted by selecting combinations from the multiple constituent elements disclosed. For example, if the problem can be solved and effects obtained even if some constituent elements are deleted from all the constituent elements shown in the embodiment, then the configuration with these deleted constituent elements can be extracted as an invention. [Explanation of Symbols]

[0065] 10...vehicle, 12...body frame, 14...cab, 16...support structure, 18a,18b...axle, 22...first bracket, 24...link arm, 24a...front end, 24b...rear end, 24c...intermediate body, 24d...base, 26...second bracket, 28...connecting member, 28a...first part, 28b...second part, 28c...third part, 30...shock absorber, 32...spring, 34...cushion rubber, 42...joint part, 44...fixing part, 46...fastening bolt, 46a,46b...bolt hole, 52...rear part, 54...front part, 56...intermediate part, 58...area where cracks are expected to occur, 60...region, 62...rib, 64...wall, 66...connecting wall, 70...support part, 80...base, 92,94...boss, 96...bolt, B1,B2...boundary.

Claims

1. A first bracket fixed to the front of the vehicle body frame extending in the longitudinal direction of the vehicle, A link arm having a front end and a rear end located at a position extending rearward from the front end, the front end being rotatably supported relative to the first bracket by a first axis along the left-right direction of the vehicle, A second bracket integrally comprises a joint portion rotatably supported relative to the rear end of the link arm by a second axis running along the left-right direction of the vehicle, and a fixing portion fixed to the front of the cab located above the vehicle frame, wherein the fixing portion has a crack-inducing portion which is intended to generate a crack due to a rotational moment with the second axis as the fulcrum when a load is applied from the front side of the vehicle, A connecting member provided on at least one of the lower surface and side surface of the second bracket, which maintains a connected state between the front and rear sides of the crack-prone portion of the second bracket when a load is applied from the front side of the vehicle and the crack occurs in the crack-prone portion of the second bracket. A support structure for the cab of a vehicle, having the following characteristics.

2. The connecting member is formed from a rolled metal plate, chain, or wire. The support structure according to claim 1.

3. The rolled metal plate is formed in a hat shape that is convex toward the second bracket. The support structure according to claim 2.

4. The aforementioned fixing part is The rear portion of the part where the crack is expected to occur is provided integrally with the joint portion on the upper side of the joint portion and is fixed to the cab with bolts, It is provided in front of the rear portion, spaced apart above the first bracket and above the link arm, fixed to the cab with bolts, and capable of maintaining its fixation to the cab when a load is applied from the front side of the vehicle, and the front portion on the front side of the area where the crack is expected to occur, An intermediate section provided between the rear section and the front section, fixed to the cab with bolts, and having the section where the crack is to occur, and Equipped with, The rear portion and the front portion are each formed to have higher strength against the rotational moment than the portion of the intermediate portion where crack formation is expected. The bolt holes in the intermediate portion are formed as the starting points of the cracks in the portion where crack occurrence is planned. The support structure according to any one of claims 1 to 3.

5. The aforementioned vehicle body frame, The aforementioned cab and, A support structure according to any one of claims 1 to 3, provided spaced apart in the left-right direction from the front part of the vehicle frame and the front part of the cab, A vehicle that possesses.

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