JP4706367B2 - Truck front suspension - Google Patents

Description

  With respect to the front suspension that supports the front wheels of the small transport vehicle, the step frame that supports the driver's seat has a smooth and stable buffer support configuration.

As the front wheel support form of the small transport vehicle, the front wheel is mounted on both ends of the front axle housing that is formed long in the horizontal direction, like the front wheel of the tractor body, and the center part of this front axle housing is center pivot pin There is known a configuration in which it is supported on the bottom of the body frame so as to be able to roll freely. In addition, a technique is known in which a pair of left and right damper springs, an air damper, and the like are provided between a vehicle body frame and an axle housing (see, for example, Patent Document 1).
Published Patent Publication No. 9-512223 (first item, FIG. 2)

  In a transport vehicle that supports a front axle housing of a horizontal configuration with front wheels mounted on both left and right sides, the step frame (body frame) that supports the driver's seat is directly connected and supported by a center pivot pin, etc. The vibration effect is insufficient, and the support state of the step frame becomes unstable in the rolling configuration.

According to the first aspect of the present invention, the front axle housing 3 is center pivoted on the lower side of the rear portion of the gate-shaped support arm 2 in which the front end both sides of the step frame 1 on both the left and right sides are supported to be swingable up and down. A support rail 5 is formed on the rear end portion through a pin 4 so as to be able to roll, and a swinging arm 7 which can be rotated by being repelled from the step frame 1 via a damper spring 6 is provided. provided, the guide roller 8 of the swing arm 7 before end and configuration of the front suspension of the truck, characterized in that the slidably supported by the support rails 5. The front axle housing 3 having front wheels mounted on both right and left ends is freely rollable with respect to the support arm 2 via a center pivot pin 4. The step frame 1 is subjected to rolling rocking, vertical rocking, and the like because it is ejected through the moving arm 7 and the like so as to rock vertically. Further, the swinging of the support arm 2 is smoothly performed by the support rail 5 at the rear end being slidably supported by the guide roller 8 of the swinging arm 7 and the rotation of the guide roller 8.
According to the second aspect of the present invention, the rear end portion of the support arm 2 that supports the axle housing 3 swings up and down via the damper spring 6 and the swing arm 7 and the like, and the step frame 1 is vibration-proofed. However, the vertical swing of the support arm 2 is prevented from shifting in the lateral direction because the guide roller 10 at the rear end is guided by the vertical guide surface of the roller guide 9 integrated with the step frame 1. .
According to the third aspect of the present invention, the support arm 2 is elastically supported by the damper spring 6 and the swing arm 7 and swings up and down. At the swing upper limit position of the support arm 2, the swing stopper 11 of the upper step frame 1 is locked, and at the swing lower limit position, the swing stopper 12 of the support arm 2 is locked to the front axle housing 3. Thus, the rolling and vertical swing regions of the front axle housing 3 are restricted.

According to the first aspect of the present invention, the center pivot pin 4 of the front axle housing 3 in which the support mechanism such as the support frame 2, the damper spring 6 that elastically supports the support frame 2, and the swing arm 7 is long over the space between the left and right front wheels. By providing it only in the central part where the position is located, the configuration can be made narrow and a low floor configuration can be simplified. Since the support frame 2 has a gate shape, it does not easily change laterally with respect to the step frame 1 even if it is subjected to rolling swing or left-right swing from the front axle housing 3 side, and the support rail 5 and the guide roller By the sliding support by 8, the vertical swinging can be performed smoothly, the impact relaxation effect or the vibration proofing effect of the step frame 1 can be enhanced, and the buffer support can be stabilized.
According to the second aspect of the present invention, the support frame 2 swings up and down against the resilient force of the damper spring 6, but the roller guide 9 on the step frame 1 side and the guide roller on the rear end of the support frame 2 By the sliding guide with 10, the vertical swing of the support frame 2 and the front axle housing 3 can be maintained smoothly, and the lateral displacement can be restricted to make the width of the support frame 2 narrow.
In the third aspect of the present invention, since the vertical swing of the support arm 2 is locked by the stoppers 11 and 12 on both the left and right sides, the step or the vibration damping function by the damper spring 6 is maintained smoothly. A stable support structure can be obtained by locking the limit position of the vertical swing of the frame 1.

Based on the illustrated example, in the transport vehicle, a cabin 20 that covers a front driver's seat 15, a seat floor 16, a step floor 17, a dashboard 18, a steering handle 19, and the like is mounted on the step frame 1. A front axle housing 3 for mounting a pair of left and right front wheels 21 on a front wheel shaft 22 is provided below the step frame 1. On the rear side of the step frame 1, a chassis frame 26 in which a dump carrier 23, an engine 24, a rear wheel 25 and the like are arranged is connected by a rolling shaft 27. The rolling shaft 27 is provided at a central portion in the vehicle width direction, and is configured such that the step frame 1 side and the chassis frame 26 side can be rotated and rotated relatively. A transmission mechanism such as the engine 24, the torque converter 28, and the transmission case 29 is disposed along the lower center portion of the chassis frame 26. The rear wheel 25 is mounted on the rear wheel shaft 31 of the rear axle housing 30 integrated on the left and right sides of the transmission case 29. Further, a front wheel transmission shaft 32 is provided from one side of the transmission case 29 to the front side so that the differential gear in the front wheel side differential case 45 at the center of the front axle housing 3 can be interlocked to perform driving traveling in the front and rear four-wheel drive mode. It can be carried out. The dump carrier 23 is supported around the dump shaft 34 at the rear of the chassis frame 26 so as to be raised and lowered, and is configured to be raised and lowered by expansion and contraction due to the hydraulic pressure of the dump cylinder 35. Further, the front wheel 21 is steered by the steering handle 19 in conjunction with a steering case 36 that is slidably supported at both ends of the front axle housing 3.

  The step frame 1 is formed from a square pipe material in the shape of a girder, and is provided below the long side portion along the front-rear direction so that the center portion of the front axle housing 3 intersects in the lateral direction. . The support arm 2 provided between the step frame 1 and the front axle housing 3 is formed in a substantially gate shape or a girder shape in a plan view, and both side portions of the front end are formed on a bracket 40 integrated with the step frame 1. On the other hand, the support shaft 41 in the horizontal direction and the rubber bush 42 fitted thereto are interposed, so that the shaft can be turned up and down and is supported in a vibration-proof manner. The support arm 2 is formed of a square pipe material on both the left and right sides, and the rear end portion is integrally constituted by a support plate 43 that supports the center pivot pin 4, a support bar 44 that provides the support rail 5, and the like. Thus, a gate-shaped rigid frame is used. An upper end portion of a pivot hanger 47 that covers a center differential case 45 formed at the center portion of the front axle housing 3 and is fastened with a bolt 46 is attached to the support plate 43 by a center pivot pin 4 extending in the front-rear direction. It is mounted and supported so that it can move freely. The center pivot pin 4 is rotatably fitted to a pin boss portion at the upper end of the pivot hanger 47 so that the front and rear end portions are supported by the support plate 43. Such a support arm 2 is formed so as to extend from the support shaft 41 in front of the front axle housing 3 so as to extend beyond the upper part and to the rear, and the upper part of the front axle housing 3 is supported by the center pivot pin 4. In this rear position, the support rail 5 of the support bar 44 and the guide roller 10 are supported and guided so as to be swingable. A pair of left and right support rails 5 extending in the front-rear direction are formed on the upper surface of the support bar 44, and the guide roller 8 of the swing arm 7 on the step frame 1 side is slidably supported on the upper surface of the support rail 5. A pair of left and right guide rollers 10 that are rotatable around a roller pin 48 along the front-rear direction is disposed on the rear side of the support bar 44 so as to sandwich the outer surface of the pair of left and right roller guides 9 integrated with the step frame 1. In this manner, the guide is slidable up and down. Further, a bracket 49 is projected from the left and right outer portions of the support arm 2, and a swing stopper 12 is provided on the front end portion so as to face the front axle housing 3. The swing stopper 12 can also be provided with a rubber damper 50 on the locking surface with the front axle housing 3. The vertical swing area of the front axle housing 3 that swings up and down around the center pivot pin 4 is locked.

  A damper spring 6, a swing arm 7, and the like disposed along the center portion of the step frame 1 are configured on the upper portion of the support arm 2. A pair of left and right swinging arms 7 are rotatably supported around an arm shaft 51 supported between the left and right roller guides 9. A rear end portion of the damper rod 52 along the front-rear direction is connected to the upper portion of the swing arm 7 by a connection pin 53, and a rod hole 55 of a frame bar 54 connected between the left and right step frames 1 is inserted. A front end receiving seat 56 of the damper spring 6 fitted to the damper rod 52 is joined to the front side of the frame bar 54, and a spring for locking the front end receiving seat 57 of the damper spring 6 to the front end portion of the damper rod 52. A stopper 58 is provided, and the spring force of the left and right damper springs 6 can be adjusted by adjusting the spring stopper 58. Further, the damper spring 6 and the swing arm 7 are configured as low as possible in the space between the step frames 1 on both the left and right sides. The support arm 2 provided on the lower side of the step frame 1 is configured to be able to swing up and down at the left and right outer portions of the step frame 1, and the relationship between the support rail 5 and the guide roller 8 and the guide roller 10 and the roller. Except for the relationship of the guides 9 and the like, they are arranged so as not to contact or interfere with each other. Further, a swing stopper 11 for locking the upward swing range of the support arm 2 is provided so as to protrude to the outside of the step frame 1, and a rubber damper 59 is provided on the locking surface with the support frame 2. .

  A rolling shaft 27 that connects between the rear end portion of the step frame 1 and the front end portion of the chassis frame 26 is provided so as to protrude rearward from the central portion of the horizontal rail 61 at the rear end of the step frame 1. At the rear part of the rolling shaft 27, a fixed connecting cylinder 63 is rotatably fitted to the central part of the crosspiece 62 at the front end of the chassis frame 26, and both the frames 1 and 26 rotate around the rolling shaft 27. Move. At the front end portion and the rear end portion of the connecting cylinder 63, rubber rubber seats 64 and 65, which are rubber ring seats, are interposed, and are fastened to the washer 66 by tightening bolts 68. The relationship between the rolling shaft 27 and the connecting cylinder 63 eliminates play in the longitudinal direction and absorbs the shock even when the transport vehicle vibrates greatly, so that the ride comfort of the driver is maintained well. The relative rolling rotation area between the step frame 1 and the chassis frame 26 around the rolling shaft 27 is fixed to the frame end 70 at the left and right rear ends of the step frame 1 and the front end of the chassis frame 26. The stoppers 69 are opposed to each other with a predetermined interval in the vertical direction, and when the rolling rotation exceeds a certain level, the stoppers 69 and the frame ends 70 are locked and integrated. It is intended to stabilize the entire transport vehicle.

By driving the engine 24, the rear wheel shaft 31 and the rear wheel 25 are driven through interlocking in the torque converter 28, the transmission case 29, and the like, and further, the front wheel shaft 22 and the front wheel 21 are driven through the front wheel transmission shaft 32. Can travel. The driver drives in the driver's seat 15 on the step frame 1, but when the road surface or the like changes during driving, the difference between the front wheel 21 and the rear wheel 25 causes a difference between the step frame 1 and the chassis frame 26. Torsion is absorbed by rolling rotation about the rolling shaft 27.
Relative rocking or vibration between the front axle housing 3 of the front wheel 21 and the step frame 1 during such traveling is absorbed by the action of the damper spring 6. The front axle housing 3 swings up and down and rolls around the center pivot pin 4. The center pivot pin 4 swings up and down around the support shaft 41 integrally with the support arm 2. The support shaft 41 is supported via a rubber bush 42 to perform a buffering action, and the rear end portion of the support arm 2 is a rocking spring that is springed by the damper spring 6 at the support rail 5 portion. The guide roller 8 of the moving arm 7 is guided and supported so as to be slidable back and forth, and the guide roller 10 is slidably guided by a vertical roller guide 9 integrated with the step frame 1. By the guides of these guide rollers 8 and 10, the support arm 2 is smoothly swung up or down, and the displacement in the left-right direction is restricted. When the relative vertical swing of the support arm 2 is increased, the support arm 2 is brought into contact with the swing stopper 11 between the step frame 1 and the front axle housing 3 that is provided facing the top and bottom. Since the swing range is restricted by contact, the step frame 1 can be maintained in a stable running posture without being swung or tilted greatly.

  In such a support structure of the front axle housing 3, the support arm 2 having a substantially gate shape in plan view, the damper spring 6, and the swing arm 7 are provided along the central portion of the front axle housing 3. The configuration width can be narrowed. In addition, since a mechanism such as a damper spring 6 is formed between the support frame 2 and the step frame 1 along the upper portion, the vertical difference between the upper step frame 1 and the lower front axle housing 3 ( The step frame 1 having a low floor shape can be configured by reducing the bulkiness. Moreover, the center of gravity can be lowered to improve the running stability.

The side view of a front-wheel support arm part. The front view. The plan view and a partially enlarged plan view. FIG. The perspective view of the swing arm part. The side view of a transport vehicle. The plan view.

1 Step Frame 2 Support Arm 3 Front Axle Housing 4 Center Pivot Pin 5 Support Rail 6 Damper Spring 7 Swing Arm 8 Guide Roller 9 Roller Guide 10 Guide Roller

Claims (3)

A front axle housing (3) is mounted on a center pivot pin (4) on the lower side of the rear part of a gate-shaped support arm (2) that supports both side portions of the front end so as to swing up and down with respect to the step frames (1) on both the left and right sides. ), And a support rail (5) is formed on the rear end portion. The step frame (1) is repelled via a damper spring (6) to be rotatable. the provided oscillating arm (7), the front suspension of the truck, characterized in that the guide rollers of the swing arm (7) before the end (8) and slidably supported on the support rail (5).   A guide roller (10) that slides with respect to a vertical guide surface of a roller guide (9) integral with the step frame (1) is provided at the rear end of the support arm (2). The front suspension of the transport vehicle according to claim 1.   Between the left and right side portions of the support arm (2), the frame (1) portion opposed to the upper side portion, and the front axle housing (3) portion opposed to the lower side portion, these relative vertical swings. The suspension according to claim 1 or 2, further comprising a rocking stopper (11), (12) capable of stopping the suspension.

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