JP2009248583A - Vehicle cross member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle cross member for securing well-balanced rigidity and strength without increasing the weight of a vehicle body by efficiently dispersing a load. <P>SOLUTION: The vehicle cross member 9b is fixed to a pair of right and left side rails 8 extending in a vehicle longitudinal direction to form a ladder type chassis frame with the side rails 8 connected to each other in a vehicle cross direction. A first member 1 is fixed to the inner face of a web 8a of one of the pair of right and left side rails 8, and a second member 2 is fixed to the inner face of a web 8a of the other. a clutch deice 3 is mounted between the first member 1 and the second member 2. The torque transmission property of the clutch device 3 is set so that, when torsion torque of a predetermined value or greater works on the pair of right and left side rails 8, the clutch device 3 slips in the peripheral direction of the cross member 9b to release the torsion torque. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a cross member constituting a chassis frame of a vehicle.

  Conventionally, as a chassis frame of a vehicle, a pair of left and right side rails extending in the vehicle front-rear direction and connected in the vehicle width direction by a cross member and formed in a ladder shape is widely used. Such a cross member of the chassis frame mainly has a function of maintaining a distance between the left and right side rails against the tensile force in the vehicle width direction, and a twist of the side rails against a moment about the cross member as a rotation axis. It has a function to suppress

  For example, in Patent Document 1, a cross member having a substantially U-shaped cross section is provided between a pair of side members (side rails) provided along the longitudinal direction of the vehicle body so as to open to one side in the longitudinal direction of the vehicle body. The arranged chassis frame structure is shown. In this technique, the side member and the cross member are connected via a gusset to increase the rigidity of the joint, particularly the torsional rigidity in the rotational direction about the cross member.

Patent Document 2 shows a structure in which a pipe-like cross member is installed between a pair of left and right side frames. In this technique, the cross-sectional shape of the cross member is a circular closed cross-section, thereby improving the cross-sectional performance and improving the member rigidity.
As described above, various shapes have been proposed for the cross member of the chassis frame in accordance with the use and purpose of use of the vehicle.
JP 2003-252235 A Japanese Patent Laid-Open No. 9-222102

Incidentally, the rigidity and strength required for the cross member are set according to the running performance of the vehicle body, for example, the allowable displacement in the vehicle width direction. Therefore, the size of the cross member has to be increased in order to increase the rigidity and strength of a vehicle that is expected to have a high load, and the vehicle body weight of the entire chassis frame increases.
On the other hand, paying attention to the load distribution in the entire chassis frame, the required rigidity and strength differ depending on the position of the cross member, and the ratio of the load sharing is biased. Therefore, if the load can be distributed and leveled over the entire chassis frame, local stress concentration can be reduced at high loads.

  The present invention has been made in view of such problems, and provides a cross member for a vehicle that can efficiently distribute a load and ensure rigidity and strength in a balanced manner without increasing the weight of a vehicle body. For the purpose.

  In order to achieve the above object, a cross member of a vehicle according to a first aspect of the present invention is fixed to a pair of left and right side rails extending in the vehicle front-rear direction and each having a U-shaped cross section. A cross member of a vehicle that forms a ladder-type chassis frame by connecting them in the vehicle width direction, and is a first member (first member) fixed to the inner surface of the web on either the left or right side of the pair of left and right side rails One pipe cloth), a second member (second pipe cloth) fixed to the web inner surface of the other of the pair of left and right side rails, and provided separately from the first member, the first member, and the first member When the torsional torque of a predetermined value or more is applied to the pair of left and right side rails, they are slipped in the circumferential direction of the cross member to release the torsional torque. It is characterized in that a latching device.

Regarding the clutch device, when the torsional torque acting on the pair of left and right side rails is less than a predetermined value, it is preferable to connect the first member and the second member.
The twisted torque may be released by slipping in a circumferential direction of the cross member when the pair of left and right side rails are twisted by a predetermined amount or more. In this case, it is preferable that the first member and the second member are connected when a twist less than a predetermined amount occurs in the pair of left and right side rails.

  According to a second aspect of the present invention, the cross member of the vehicle according to the second aspect of the present invention includes the first press contact in which the first member is extended in the radial direction at the inner edge in the vehicle width direction. The second member extends in the radial direction at an inner edge in the vehicle width direction and has a second press contact portion facing the first press contact portion, and the clutch device includes the first press contact portion. A clutch disc interposed between the inner surface in the vehicle width direction of the portion and the inner surface in the vehicle width direction of the second pressure contact portion, and the vehicle in at least one of the first pressure contact portion and the second pressure contact portion The elastic member (spacer) mounted on the outer surface in the width direction, the first pressure contact portion, the second pressure contact portion, the clutch disk, and the elastic member are mounted, and the elastic member is pressed toward the inner side in the vehicle width direction. Clamp member (case It is characterized by having, when.

  According to a third aspect of the present invention, in addition to the structure of the first or second aspect, the cross member of the vehicle according to the present invention is interposed in a fixing portion between the first member, the second member, and the web inner surface. A bracket is further provided, wherein the bracket is short in the vertical direction and long in the vehicle front-rear direction, and is fastened and fixed to an intermediate portion in the vertical direction on the web inner surface of the side rail.

  According to a fourth aspect of the present invention, in the vehicle cross member according to the present invention, in addition to the structure according to any one of the first to third aspects, the chassis frame is disposed at intervals in the longitudinal direction of the vehicle. The first member, the second member, and the clutch device are applied to a No. 2 cross member located second from the front among the plurality of cross members. It is characterized by.

  Note that, in a vehicle including a cab and a body, among the plurality of cross members disposed below the cab, the foremost one is the No. 1 cross member, and the plurality of cross members disposed below the body. The No. 2 cross member is the foremost cross member. The No. 2 cross member is a cross member disposed at a position closest to the front axle of the vehicle.

  According to a fifth aspect of the vehicle cross member of the present invention, in addition to the configuration of any one of the first to fourth aspects, the cross-sectional shapes of the first member and the second member are cylindrical. It is characterized by being formed.

  According to the cross member of the vehicle of the present invention (Claim 1), the clutch device interposed in the middle portion of the divided cross member releases the torsional torque generated between the pair of left and right side rails that exceeds the predetermined value. Therefore, it is possible to reduce the stress generated in the fixing portion between the first member and the second member and the side rail, and to protect the cross member. Further, the torsional torque can be borne by the cross member when the load is low, and the torsional torque can be distributed to other parts of the chassis frame when the load is high.

  Further, according to the cross member of the vehicle of the present invention (Claim 2), since the clutch disk is pressed between the first press contact portion and the second press contact portion of the cross member, it is manufactured. The cost concerning this is low and the operation reliability is high. Further, since the degree of engagement of the clutch disk is adjusted by pressing the elastic member with the clamp member, a predetermined value at which the torsion torque is released can be easily set.

In addition, by changing the dimensions, material, type, etc. of the elastic member, the predetermined value can be changed without changing other members, so the structure of this cross member is common among vehicles of different vehicle types and specifications. Can be That is, standardization of the product becomes easy, and the manufacturing cost can be further reduced.
Further, according to the cross member of the vehicle of the present invention (Claim 3), even if vertical bending deformation or torsional deformation occurs in the side rail, stress generation due to the deformation is small in the intermediate portion of the side rail web. Therefore, the load acting on the fastener that fastens and fixes the bracket is mainly a shearing force, and the bracket, the fastener, the web, and the like are advantageous in strength.

  Further, according to the cross member of the vehicle of the present invention (Claim 4), the first member, the second member, and the clutch device are applied to the No. 2 cross member in which the torsion torque is most likely to increase. By distributing the load to the cross members, the load distribution can be made uniform throughout the chassis frame, and it is easy to set a balanced rigidity and strength in each member constituting the chassis frame.

  Further, according to the cross member of the vehicle of the present invention (Claim 5), the torsional torque is efficiently transmitted in the engaged state of the clutch device by forming the cross-sectional shapes of the first member and the second member into a cylindrical shape. can do. Further, when the clutch device is in a slip state (or in an open state), the transmission amount of the torsion torque can be easily limited (or the torsion torque is cut off).

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 6 are views for explaining a cross member of a vehicle according to an embodiment of the present invention, and FIG. 1 is a schematic perspective view showing an entire configuration of a chassis frame to which the cross member is applied. 2 is a perspective view showing the overall configuration of the cross member, FIG. 3 is a cross-sectional view of the cross member, FIG. 4 is a front view of a bracket related to the cross member, and FIG. 5 is a torque transmission characteristic of the clutch device in the cross member. FIG. 6 is a schematic diagram for explaining the twisting behavior of the chassis frame to which the present cross member is applied.
FIG. 7 is a cross-sectional view of a vehicle cross member as a modification of the present invention.

[1. Constitution]
[overall structure]
The cross member according to the present invention is applied to a ladder-type chassis frame 10 as shown in FIG. The chassis frame 10 includes a side rail 8 and a cross member 9.

  The side rails 8 are members that extend in the vehicle front-rear direction, and two side rails 8 are provided so as to form a pair on the left and right sides at a predetermined interval in the vehicle width direction. Each cross-sectional shape is formed in a U-shaped channel shape, and a flange 8b extends from the upper and lower ends of the vertically oriented web 8a toward the inside in the vehicle width direction. That is, the side rails 8 are arranged so that the inner surfaces of the webs 8a face each other.

The cross member 9 is a member that connects the left and right side rails 8 in the vehicle width direction, and a plurality of the cross members 9 are arranged at intervals in the vehicle front-rear direction. These cross members 9 are, in order from the front of the vehicle, No. 1 cross member 9a, No. 2 cross member 9b, No. 3 cross member 9c, No. 4 cross member 9d, No. 5 cross member 9e, and end cross member 9f. is called.
In the present embodiment, six cross members 9 are provided on the chassis frame 10, but the number of the cross members 9 to be provided is generally the length of the wheel base (WB) and the type of bodywork (flat Body, dump, tank truck, etc.)

As shown in FIG. 1, the No. 1 cross member 9a is the cross member 9 located at the front end of the chassis frame 10, and is a member to which the front bumper of the vehicle is fixed. On the other hand, the end cross member 9 f is located at the rear end of the chassis frame 10.
The No. 2 cross member 9b to the No. 5 cross member 9e are provided between the No. 1 cross member 9a and the end cross member 9f. These cross members 9b to 9e are located below the body behind the cab 13 of the vehicle, and the one closest to the adjacent portion between the cab 13 and the body is the No. 2 cross member 9b.

  As schematically shown in FIG. 1, the front axle 14 to which the front wheel 12 of the vehicle is pivotally attached is fixed to the side rail 8 between the No. 1 cross member 9a and the No. 2 cross member 9b. The rear axle 15 is fixed to the side rail 8 between the No. 4 cross member 9d and the No. 5 cross member 9e. In addition, since the vehicle running engine and the transmission are mounted between the No. 1 cross member 9a and the No. 2 cross member 9b, the distance between the cross members 9a and 9b is different from that of the other cross members 9b. It is larger than the adjacent interval. Further, the No. 2 cross member 9b is closest to the fixed position of the front axle 14, and is most susceptible to the torsional displacement of the chassis frame 10 during traveling.

  The cross member according to the present invention is applied as No. 2 cross member 9b. Hereinafter, the No. 2 cross member 9b is also simply referred to as a cross member 9b. As shown in FIG. 2, the cross member 9 b includes a first pipe cross (first member) 1, a second pipe cross (second member) 2, a clutch device 3, and a bracket 4.

[First and second pipe cross]
The first pipe cloth 1 and the second pipe cloth 2 are both cylindrical members having the same diameter, and are arranged so that the ends face each other in the vicinity of the center in the vehicle width direction. The first pipe cloth 1 and the second pipe cloth 2 are connected via a collar 11.

The collar 11 is a cylindrical member having the same outer peripheral radius as the inner peripheral surfaces of the first pipe cloth 1 and the second pipe cloth 2. The collar 11 is inserted and fixed with respect to one of the first pipe cloth 1 and the second pipe cloth 2, and is slidably inserted with respect to the other. That is, the collar 11 is in sliding contact with the other inner peripheral surface that is not fixed.
In this way, by connecting the first pipe cloth 1 and the second pipe cloth 2 with the collar 11, the cylindrical axes of the first pipe cloth 1 and the second pipe cloth 2 are located on the same straight line. . Hereinafter, both of these cylindrical axes are referred to as axis C. Further, since the collar 11 does not restrict the movement of the first pipe cloth 1 and the second pipe cloth 2 in the direction away from each other, the tensile force in the direction along the axis C is not transmitted to the cross member 9b.

[bracket]
Each of the first pipe cloth 1 and the second pipe cloth 2 is fixed to the inner surface of the web 8 a in the side rail 8 via the bracket 4. As shown in FIG. 4, the shape of the bracket 4 is short in the vertical direction and long in the vehicle front-rear direction. As shown in FIG. 2, the bracket 4 is fastened and fixed to an intermediate portion in the vertical direction on the inner surface of the web 8 a of the side rail 8. That is, the fastening position of the bracket 4 is near the center in the vertical direction of the web 8a as shown in FIG.

  A fastener such as a bolt or a nut is used for fastening the bracket 4 to the web 8a.

[Clutch device]
A clutch device 3 is interposed between the first pipe cloth 1 and the second pipe cloth 2. FIG. 3 shows a cross-sectional view of a portion where the clutch device 3 is interposed. First, a flange-shaped first press-contact portion 1a extending in the radial direction (radial direction) is formed on the inner edge of the first pipe cloth 1 in the vehicle width direction. On the other hand, a second press-contact portion 2a having the same shape as the first press-contact portion 1a is also formed at the inner edge in the vehicle width direction of the second pipe cloth 2. The first press contact portion 1a and the second press contact portion 2a face each other in parallel.

  A clutch disk 5 is interposed between the first pressure contact portion 1a and the second pressure contact portion 2a in a pressure contact state. The clutch disk 5 is a friction material (clutch facing) for transmitting a friction force between the first press contact portion 1 a and the second press contact portion 2 a, and is formed in an annular shape so as to surround the outer periphery of the collar 11. As a result, the torsional torque about the axis C can be transmitted between the first pipe cloth 1 and the second pipe cloth 2. The clutch disk 5 is fixed to one of the first press contact portion 1a and the second press contact portion 2a.

The torque transmission characteristics of the clutch disk 5 are shown in FIG. In the present embodiment, as indicated by symbol A in FIG. 5, when the twist angle θ of the first pipe cross 1 and the second pipe cross 2 is less than a predetermined angle θ ₀ , the clutch disk 5 slips. The torsional torque is transmitted. Further, when the twist angle θ becomes equal to or greater than the predetermined angle θ ₀ , the clutch disk 5 starts to slip, so that the twist torque greater than the predetermined value T ₀ is not transmitted.

[Case, Spacer]
A spacer (elastic member) 6 is mounted on each outer surface in the vehicle width direction of each of the first pressure contact portion 1a and the second pressure contact portion 2a. Further, a case (clamp member) 7 surrounds the outside of the spacer 6. It is attached.
The external appearance of the case 7 has a hollow cylindrical shape through which the first pipe cloth 1 and the second pipe cloth 2 can be inserted, and as shown in FIG. It is formed by that. The size of the case 7 is set so that the gap between the inner surface and the outer surface in the vehicle width direction of the first press contact portion 1 a and the second press contact portion 2 a is smaller than the thickness of the spacer 6.

  As a result, the spacer 6 is pressed by the inner surface of the case 7 toward the inner side in the vehicle width direction with a predetermined pressure, and acts to press the first press contact portion 1a and the second press contact portion 2a together. The spacer 6 is an elastic object, and for example, various elastic members such as an elastic rubber, an elastic polymer, a coil spring, a leaf spring, and a disc spring may be used.

[2. Action]
The behavior when torsional torque acts on the cross member 9b according to the present invention will be described below. The torsional torque referred to here is a torsional moment in the rotational direction about an arbitrary axis extending in the vehicle width direction, and is generated by the torsion of the chassis frame 10. Accordingly, the torsional torque of the cross member 9b is a torsional moment in the rotational direction about the axis C of the cross member 9b.

[When twist is small]
When a relatively slight difference in height between the left and right wheels of the front wheel 12 occurs while the vehicle is running, one of the left and right side rails 8 tends to move upward or the other tends to move downward. Therefore, in the cross member 9b, the torsional torque T _{1 having} a magnitude corresponding to the displacement of the side rail 8 fixed to the end of the first pipe cross ₁ (torque in the rotational direction about the axis C of the cross member 9b). ) Occurs. Also in the second pipe cross 2, torsion torque T ₂ magnitude corresponding to the displacement of the other side rail 8 is generated. As shown in FIG. 6, when one side rail 8 moves upward and the other side rail 8 attempts to move downward, the rotational direction of the torsional torque on the first pipe cross 1 side and the second pipe The direction of rotation of the torsional torque on the cross 2 side is reversed.

Here, when the twist of the chassis frame 10 is relatively light and the twist angle θ between the first pipe cloth 1 and the second pipe cloth 2 is less than the predetermined angle θ ₀ , the first pressure contact portion 1a Both torsional torques T ₁ and T ₂ are transmitted to each other via the clutch device 3 with the second pressure contact portion 2a. Accordingly, torsional torque with the magnitude of the difference between the torsion torque T ₁ of the first pipe-cross 1 side and torsion torque T ₂ of the second pipe cross 2 side | as the internal stress of the cross member 9b | T ₁ -T ₂ Will be distributed. That is, when the twist is relatively small, the cross member 9b functions to keep the shape of the chassis frame 10 against the twist torque.

[When twist is large]
When the difference in height between the left and right front wheels 12 increases during running on rough roads and muddy grounds, both the torsion torque T ₁ generated on the first pipe cross 1 side and the torsion torque T ₂ generated on the second pipe cross 2 side increase. The torsion torque | T ₁ -T ₂ | borne by the cross member 9b is further increased.

On the other hand, when the chassis frame 10 is twisted and the side rails 8 are moved in the vertical direction, the distance between the left and right side rails 8 is increased. For example, as shown in FIG. 6, when the distance between the side rails 8 of the left and right in a state where the torsion is not generated with L _1, the distance in a state where the torsion is generated becomes longer L ₂ than L ₁ . And this distance becomes long, so that a twist becomes large (namely, the difference in height of the front wheel 12 is large).

  Therefore, the first pipe cloth 1 and the second pipe cloth 2 move to the outside in the vehicle width direction, and in the case 7, the first pressure contact portion 1 a and the second pressure contact portion 2 a respectively move the spacer 6 outside. Acts to press. Therefore, the pressing force from the spacer 6 to the clutch disk 5 (inward in the vehicle width direction) is weakened, and the frictional force of the clutch disk 5 is weakened.

When the chassis frame 10 is twisted until the twist angle θ between the first pipe cross 1 side and the second pipe cross 2 side becomes equal to or greater than the predetermined angle θ ₀ , the clutch disk 5 starts to slip. That is, the first pressure contact portion 1a of the first pipe cloth 1 and the second pressure contact portion 2a of the second pipe cloth 2 are displaced in the circumferential direction, and the torsional torque corresponding to the displacement amount is released. Thus, the value of the torsional torque transmitted through the clutch disc 5 is reduced, a predetermined value T ₀ as shown in FIG.

Further, other cross members 9 such as No. 3 cross member 9c and No. 4 cross member 9d are caused by torsion of chassis frame 10 due to relative rotational displacement between first pipe cross 1 and second pipe cross 2 in cross member 9b. The torsional torque borne by is increased. That is, in the deformation region where the twist angle θ between the first pipe cross 1 side and the second pipe cross 2 side is equal to or greater than the predetermined angle θ _0, a part of the torsion torque that has been borne by the cross member 9b until then is another It is distributed to the cross members 9.

[3. effect]
As described above, according to the cross member 9b of the present embodiment, when the torsional deformation occurs in the chassis frame 10 and the relative twist angle θ of the left and right side rails 8 becomes equal to or greater than the predetermined angle θ ₀ , the first pipe cross 1 Since the clutch device 3 interposed between the second pipe cloth 2 and the second pipe cloth 2 slides to release the torsional torque, the stress generated in the cross member 9b and the stress generated in the fixing portion with the side rail 8 are reduced. And the cross member 9b can be protected.

Further, by slidably displacing the clutch device 3, the torsional torque of the chassis frame 10 can be borne by the other cross member 9. That is, the torsional torque at the time of high load can be distributed from the cross member 9b to other parts.
On the other hand, the clutch device 3 does not slide at a low load when the relative twist angle θ of the left and right side rails 8 is less than the predetermined angle θ ₀ , so that the torsion torque of the chassis frame 10 can be borne by the cross member 9b. .

  Moreover, in this embodiment, since the clutch disk 5 is pressed against each other between the first pipe cross 1 and the second pipe cross 2 that are separately formed, the manufacturing cost is kept low. be able to. Further, the transmission amount of the torsional torque is controlled by a mechanical structure in which the frictional force of the clutch disk 5 is reduced by utilizing the tensile force in the direction of the axis C generated in the cross member 9b due to the torsional deformation of the chassis frame 10. Therefore, there is an advantage that operation reliability is high.

It is also easy to adjust the amount of torsional torque transmitted by changing the mechanical structure. That is, it is possible to adjust the degree of slip not only by changing the frictional force on the surface of the clutch disc 5 but also by changing the size, material, type, etc. of the spacer 6. Therefore, the predetermined value T _{0 at} which the torsion torque is released can be easily set.
Further, if the dimensions and materials of the spacer 6 are changed, the predetermined value of the torsion torque to be transmitted without changing other members such as the clutch disk 5, the case 7, the first pipe cross 1, and the second pipe cross 2. T ₀ can be changed. Therefore, the structure of the cross member 9b can be shared between vehicles having different vehicle types and specifications. That is, standardization of the cross member 9 is facilitated, and manufacturing costs can be further reduced.

  In the present embodiment, both the first pipe cloth 1 and the second pipe cloth 2 are fastened and fixed to the side rail 8 via the bracket 4, and the fastening position of the bracket 4 is the vertical direction of the web 8 a of the side rail 8. Near the center. Therefore, even if vertical bending deformation or torsional deformation occurs in the chassis frame 10, the compressive tensile stress in the vehicle width direction in the vicinity of the bracket 4 is small, and it is possible to design a cross member 9b that is advantageous in strength. Furthermore, as shown in FIG. 4, since the shape of the bracket 4 is a horizontally long shape extending in the vehicle front-rear direction, the load acting on the fastener that fastens and fixes the bracket 4 is mainly a vertical shearing force. Become. That is, since the load in the direction (vehicle width direction) in which the fastener is to be pulled out is small, the fastener can be designed to be advantageous in terms of strength.

  Since the distance between the No. 1 cross member 9a and the No. 2 cross member 9b on which the engine, transmission, etc. are mounted is larger than the adjacent interval of the other cross members 9, the No. 2 cross member Torsion torque is likely to be generated in the member 9b. Further, since the No. 2 cross member 9b is disposed at the position closest to the fixed position of the front axle 14, the torsional torque is most likely to increase among the other cross members 9.

On the other hand, in this embodiment, since the clutch device 3 is interposed in such a No. 2 cross member 9b, the load distribution is distributed to the entire chassis frame 10 by distributing the load to the other cross members 9. Can be leveled. Therefore, it is easy to set a balanced rigidity and strength without local load concentration.
In the present embodiment, since the first pipe cloth 1 and the second pipe cloth 2 are formed in a cylindrical shape, the torsion torque can be efficiently transmitted when the clutch device 3 is engaged. Further, since the displacement in the circumferential direction is not restrained in the slip state of the clutch device 3, the transmission amount of the torsional torque can be easily limited.

  Thus, according to the present cross member 9, the torsional torque load can be efficiently distributed over the entire chassis frame 10, and the rigidity and strength can be secured in a well-balanced manner without increasing the vehicle body weight. .

[4. Others]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  That is, the gist of the present invention is to reduce the frictional force of the clutch disk 5 (upper limit value of the transmission amount of the torsional torque) by using the tensile force generated in the vehicle width direction along with the torsional deformation of the chassis frame 10. The point is to release the torsional torque. Therefore, it is sufficient that the clutch device 3 is provided that slips in the circumferential direction of the cross member 9 to release the torsion torque when any parameter corresponding to the torsional deformation of the chassis frame 10 exceeds a predetermined value.

In the above-described embodiment, the clutch disk 5 is described as having the torque transmission characteristic indicated by the symbol A in FIG. 5, but the torque transmission characteristic that is specifically set is not limited to this.
For example, as indicated by reference numeral B in FIG. 5, when the twist angle θ of the first pipe cloth 1 and the second pipe cloth 2 is equal to or greater than a predetermined angle θ ₀ , the torsion torque is transmitted as the twist angle θ increases. The characteristic may be set such that the amount decreases, or, as indicated by reference numeral C, the clutch disk 5 may be disengaged and completely released when the twist angle θ reaches θ ₀ ′. Such torque transmission characteristics can be set not only by changing the frictional force on the surface of the clutch disk 5 but also by changing the size, material, type, etc. of the spacer 6 as described above.

  In the above-described embodiment, the bracket 4 has a shape that is short in the vertical direction and long in the vehicle front-rear direction. This is due to the stress generated between the first pipe cloth 1 or the second pipe cloth 2 and the web 8a. It can be appropriately changed according to the size and the like. Note that a fixing method such as welding fixing may be used instead of the fixing by the fastener. Alternatively, the end portions of the first pipe cloth 1 and the second pipe cloth 2 may be directly fixed to the side rail 8 without using the bracket 4.

In the above-described embodiment, the cross member according to the present invention is applied as the No. 2 cross member 9b. However, it is of course possible to apply it as the other cross member 9. In that case, it is preferable to set the predetermined value T ₀ of the torsion torque that can be borne by each cross member 9 to a magnitude corresponding to the arrangement position.
In the above-described embodiment, the collar 11 is inserted so as to connect the first pipe cloth 1 and the second pipe cloth 2, but this can be omitted as appropriate. For example, if the outer peripheral end surfaces of the first press contact portion 1a and the second press contact portion 2a and the inner peripheral surface of the case 7 are formed to be accurately slidable, the same effects as those of the above-described embodiment can be achieved without using the collar 11. Is obtained.

  Further, in the above-described embodiment, the first pipe cloth 1 and the second pipe cloth 2 are formed as cylindrical members, but these members are slidable in the direction of the axis C with respect to each other and have some circumferential direction. The shape is not limited to this as long as the displacement is acceptable. The specific shape is the relationship between the inner peripheral surface of the first pipe cloth 1 and the second pipe cloth 2 and the outer peripheral surface of the collar 11, or the outer peripheral end surfaces of the first press contact portion 1 a and the second press contact portion 2 a and the case 7. It can set suitably from the relationship with the inner peripheral surface.

  In the above-described embodiment, the cross member 9b in which the spacer 6 is mounted on each of the first press contact portion 1a and the second press contact portion 2a has been described. However, if the spacer 6 is mounted on at least one of them. Good. For example, as shown in FIG. 7, when the spacer 6 is provided only on the outer surface in the vehicle width direction of the first pressure contact portion 1a, the outer surface in the vehicle width direction of the second pressure contact portion 2a contacts the inner surface of the case 7 '. Even in such a configuration, when torsional deformation occurs in the chassis frame 10, the first pipe cloth 1 and the second pipe cloth 2 move to the outside in the vehicle width direction, and the clutch disk 5 is moved from the spacer 6 according to the amount of movement. Since the pressing force toward the inside in the vehicle width direction is weakened, the frictional force of the clutch disk 5 is weakened. Therefore, the same effect as that of the above-described embodiment can be obtained.

  The chassis frame 10 to which the cross member according to the present invention is applied can be applied to various vehicles such as trucks such as dump trucks and van type cars, tank trucks, large / medium-sized buses, special vehicles, and freight vehicles. . In particular, it is suitable for use in vehicles that require running performance on rough roads and muddy areas.

1 is a schematic perspective view showing an overall configuration of a chassis frame to which a cross member of a vehicle according to an embodiment of the present invention is applied. 1 is a perspective view showing an overall configuration of a cross member of a vehicle according to an embodiment of the present invention. It is sectional drawing of the cross member of the vehicle which concerns on one Embodiment of this invention. It is a front view of the bracket for cross members of the vehicle concerning one embodiment of the present invention. It is a graph which shows the torque transmission characteristic of the clutch apparatus in the cross member of the vehicle which concerns on one Embodiment of this invention. It is a mimetic diagram for explaining the twisting behavior of the chassis frame to which the cross member of the vehicle concerning one embodiment of the present invention is applied. It is sectional drawing of the cross member of the vehicle as a modification of this invention.

Explanation of symbols

1 First pipe cloth (first member)
1a 1st pressure contact part 2 2nd pipe cloth (2nd member)
2a 2nd press-contact part 3 Clutch device 4 Bracket 5 Clutch disk 6 Spacer (elastic member)
7 Case (Clamp member)
8 Side rail 8a Web 8b Flange 9 Cross member 9b No.2 cross member 10 Chassis frame 11 Collar 14 Front axle

Claims (5)

A vehicle cross member that is fixed to a pair of left and right side rails that extend in the vehicle longitudinal direction and has a U-shaped cross section, and that connects the side rails in the vehicle width direction to form a ladder-type chassis frame. Because
A first member fixed to the inner surface of the web in either one of the left and right side rails;
A second member fixed to the inner surface of the web in the other of the pair of left and right side rails, and provided separately from the first member;
The torsional torque is interposed between the first member and the second member, and slips in the circumferential direction of the cross member when the torsional torque of a predetermined value or more acts on the pair of left and right side rails. And a clutch device for releasing the vehicle. The first member has a first press-contact portion extending in a radial direction at an inner edge in the vehicle width direction,
The second member has a second press-contact portion that extends in the radial direction at the inner edge in the vehicle width direction and faces the first press-contact portion,
The clutch device is
A clutch disk interposed in a pressure contact state between a vehicle width direction inner surface of the first pressure contact portion and a vehicle width direction inner surface of the second pressure contact portion;
An elastic member mounted on the outer surface in the vehicle width direction in at least one of the first pressure contact portion and the second pressure contact portion;
A clamp member that is mounted on the first pressure contact portion, the second pressure contact portion, the clutch disk, and the elastic member, and that presses the elastic member toward the inner side in the vehicle width direction. Item 4. A vehicle cross member according to Item 1. A bracket interposed between the first member, the second member, and the inner surface of the web;
3. The bracket according to claim 1, wherein the bracket is formed to be short in the vertical direction and long in the vehicle front-rear direction, and is fastened and fixed to an intermediate portion in the vertical direction of the web inner surface of the side rail. Cross member of the vehicle. The chassis frame includes a plurality of cross members disposed at intervals in the vehicle front-rear direction,
The first member, the second member, and the clutch device are applied to a No. 2 cross member located second from the front among the plurality of cross members. 4. The vehicle cross member according to any one of 3 above. The cross member of the vehicle according to any one of claims 1 to 4, wherein the first member and the second member have a cylindrical cross-sectional shape.

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