JPH0561128B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to an elastic support device for the seat of an agricultural tractor.

(b) Prior Art A support device for the seat of an agricultural tractor using parallel links has been known for some time. For example, Utility Model Application Publication No. 55-36096,
This is as disclosed in Japanese Utility Model Application Publication No. 57-24142. but,
When the seat was supported by parallel links, there was a problem in that when the operator sat down and the seat was lowered, the seat position would move forward.

Also used as a seat support device for agricultural tractors.
Those using cross-links were also known. For example, there are Japanese Utility Model Application Publication No. 60-95334 and Japanese Utility Model Application Publication No. 59-128430.

Furthermore, a technique for bending and expanding the seat spring as the seat is lowered is known as a technique described in Japanese Patent Application Laid-Open No. 48-98521.

(C) Problems to be Solved by the Invention The purpose of the present invention is to modify the conventional cross-link type seat suspension structure to provide a sufficient vertical width between the top and bottom of the seat and to prevent vertical vibration. This is a seat suspension device that provides an appropriate cushioning force.

In addition, in the prior art, one of the lower ends of the cross link was able to slide back and forth, making smooth vertical movement impossible. Therefore, in the present invention, the lower ends of the cross link are pivoted on top of the slide guide both front and rear. This cross link is pivotally connected to the tip of a rotating arm that protrudes to rotate freely, thereby eliminating sliding movement of the lower end of the cross link within the elongated hole and allowing smooth vertical movement.

In addition, the stopper at the bottom of the vertical movement of the seat is
This is accomplished not by the engagement of the long hole and the lower end of the cross link as in the prior art, but by the above-mentioned contact of the rotating arm with the top surface of the slide guide. It is designed to reliably act as a stopper at the lower end even when the seat moves up and down violently.

(d) Means for Solving the Problems The objects of the present invention are as described above, and the structure for achieving the objects will now be explained.

Cross links 3 and 4 whose front and rear centers are supported by cross pins 7 are arranged on the left and right, and the seat 1 is supported by the left and right cross links 3 and 4.
A seat spring 6 is disposed between the front and rear ends of cross links 3 and 4 that open and close back and forth as the seat 1 descends and rises, and the seat spring 6 expands and contracts as the seat 1 descends and rises to absorb shock. As the cross links 3 and 4 descend,
The cross pin 7 that pivots the seat 1 is lowered, and the cross pin 7 contacts the center of the front and rear length of the seat spring 6, so that the seat spring 6, which has been extended due to the lowering of the seat 1, is further bent and extended. .

Moreover, the rotating arm shafts 14 and 15 of the rotating arms 12 and 13 that pivotally support the lower ends of the cross links 3 and 4
, bearing rings 30, 4 fixed on the slide guide 17 for adjusting the entire seat device by sliding it back and forth.
2, which is pivotally supported by a bearing.

Further, the rotating arms 12 and 13 rotate downward and come into contact with the upper surface of the slide guide 17, thereby forming a stopper on the lowering side of the seat 1.

(e) Embodiments and operations The purpose and structure of the present invention are as described above, and the operations of the present invention will be explained together with the structure of the embodiments shown in the attached drawings.

FIG. 1 is a side view of the seat suspension device of the present invention, FIG. 2 is a partially sectional front view, FIG. 3 is a rear view, and FIG. 4 is a drawing of the spring curve of the seat spring.

The seat suspension structure of the present invention will be explained step by step from the bottom.

In the agricultural tractor, the seat 1 is arranged on the transmission case, particularly on the hydraulic case 41. A bracket 27 is placed on the hydraulic case 41, and left and right slide rails 19 are fixedly mounted on the bracket 27.

Furthermore, front and rear fender brackets 35 and 36 are protruded from the bracket 27 to extend left and right. The inner surfaces of the left and right fenders are fixed to the left and right ends of the fender brackets 35 and 36. Further, a breather device 26 is suspended and fixed to the lower side of the rear fender bracket 36.

The breather device 26 allows air to enter and exit the transmission case and the hydraulic case 41 by piping from an opening at the upper end of the hydraulic case 41.

A slide guide 17 is inserted by fitting into the left and right slide rails 19. Since the slide guide 17 holds the slide rail 19,
It does not come off in the vertical direction. The left and right slide guides 17 have inward connecting brackets 32,
31 is extended, and the left and right connecting brackets 32, 31 are overlapped and fastened with bolts to integrate the left and right.

The reason why the left and right slide guides 17 are configured to be integrated later is that it is easy to match the interval between the left and right slide guides 17 with the slide rail 19. With this configuration, the distance between the slide rail 19 and the slide guide 17 is established reliably, and sliding is performed smoothly without resistance.

Further, on the slide guide 17, the lower ends of the front and rear rotating arm shafts 14, 15 are pivotally supported.
Front and rear bearing rings 30, 42 are fixedly installed, and a rotating arm shaft 14,
15, use the left and right slide guides 1.
7 needs to be spaced wider. This is because the rotating arm shafts 14 and 15 have the left and right rotating arms 12 and the spring-supported rotating arms 21 and 2 in the middle.
0 is fixed by welding and cannot be inserted from the side of the bearing rings 30, 42. Therefore, the rotating arm shafts 14 and 15 are disposed between them, and the bearing rings 30 and 42 are inserted into these from the left and right for assembly.

As mentioned above, the left and right slide guides 17, 17
are configured separately and later connected to the connecting brackets 32, 3.
By assembling and integrating the slides 1 and 1, there is an effect that sliding can be performed smoothly and that the rotation arm shafts 14 and 15 can be pivotally supported on the slide guide 17.

In order to fix the slide guide 17, which slides back and forth on the slide rail 19, at a desired position, a lock handle 28 is configured to be rotatable, and the tip of the lock handle 28 is connected to the slide guide 17 and the slide rail 19. The slide is configured to be locked by fitting into lock recesses provided in stages on both sides.

The left and right bearing rings 30 on the slide guide 17,
On the rotating arm shaft 14 which is pivotally supported between the bearing rings 30 and 30, the rotating arms 12, 12 immediately inside the bearing ring 30 and the spring supporting rotating arms 21, 21 near the center are fixed at an angle. There is. Similarly, rotating arms 13, 13 and spring supporting rotating arms 20, 20 are fixed to the rear rotating arm shaft 15, and a pin 22 between the front spring supporting rotating arms 21, Seat springs 6, 6 are interposed between the pin 24 between the spring support rotation arms 20 at the rear.

In this embodiment, there are two seat springs 6, but in reality there may be any number of seat springs.

Further, between the position above the rotation arm axis 14 of the front spring support rotation arm 21 and the extending portion below the rotation arm axis 15 of the rear spring support rotation arm 20, there is a A synchronization link 5 is interposed so that the rotation arms 12 and 13 rotate in synchronization and rotate by the same degree.

With the rotating arms 12 and 13 configured as described above,
Bearing rings 29, 4 at the tips of the rotating arms 12, 13
The lower ends of cross links 3 and 4 are pivoted to 3 to move up and down, but the seat 1 is synchronized by a tuning link 5 so that it does not tilt only forward or backward. .

Two cross links 3 and 4 are placed side by side on the left and right sides. A cross pin 7 is inserted into the intersection of the cross links 3 and 4 to pivotally support both links. The spacer tube 47 into which the cross pin 7 is inserted maintains the distance between the left and right cross links 3 and 4. With this configuration, the cross links 3 and 4 move up and down while expanding and contracting.

However, since the width of the upper ends of the cross links 3 and 4 changes, it is not possible to connect them directly to a rigid body. Therefore, in this seat suspension structure, the tip of the cross link 4 is pivotally connected to a part of the seat frame 2, and the rear end of the cross link 3 is slidable between the seat frame 2 and the rotating roller 18. That is.

With this configuration, when the seat frame 2 is lowered by the operator's weight, the seat frame 2 moves slightly forward together with the cross link 4, and the cross link 3 is moved by the rotating roller 18.
It slides rearward with respect to the seat frame 2.
Also, the cross pin 7 and spacer 47 of the central pivot of the cross links 3 and 4 gradually move downward,
Pin 2 of front and rear spring support rotation arms 21, 20
Seat springs 6, 6 installed between 2 and 24
Start pushing the top center of the seat springs 6, 6.
By increasing the length of the spring, the spring biasing force is increased.

When no operator is sitting on the seat 1, the cross pins 7 of the cross links 3, 4 do not contact the seat springs 6, 6, the seat springs 6, 6 are contracted, and the shaft 44 of the rotating roller 18 is attached to the seat. The seat 1 stops rising at the position where it engages with the stopper stepped portion 2a of the frame 2. Therefore, the center portions of the seat springs 6, 6 are bent only when the operator is riding the vehicle, so accidents such as breakage of the springs do not occur.

As described above, when the seat springs 6, 6 are extended and the seat 1 is lowered to a certain extent, the cross pin 7 abuts and locks on the center upper surface of the seat springs 6, 6, causing the seat springs 6, 6 to move in the shape of a dogleg. By bending it into a shape, the degree of elongation of the seat springs 6, 6 can be increased, and the fourth
As shown in the spring curves of the seat springs 6, 6 shown in the figure, an unprecedented relationship between load and deflection can be obtained, and sufficient cushioning force can be obtained with short seat springs 6, 6 in narrow spaces. It is possible.

In addition, when an operator is sitting on the seat 1 and the seat 1 is lowered more than necessary due to a large impact, the stopper is activated by rotating the rotating arm 12 that is pivotally supported on the slide guide 17.
By coming into contact with the upper surface of 7, it forms a stopper that prevents further rotation.

Further, the seat 1 is fixed to the seat frame 2.

Although it is called fixed, it is not completely fixed, but only the front end is pivoted so that it can be rotated and laid down to prevent the surface of the seat 1 from deteriorating due to sunlight when the agricultural tractor is not in use. It is. The front end of the seat 1 is pivotably supported by a pin 8 so that it can be inserted into three adjustment holes in the seat frame 2. Also, the rear end of seat 1 and seat frame 2
A cushion rubber 25 is interposed between the sheet 1 and the cushion rubber 25.
This means that the shock is reduced.

Referring to FIG. 2, a pivot point between the front end of the cross link 4 and the seat frame 2 will be explained.

A pivot tube 35 is fixedly installed between the left and right cross links 4, 4, and pivot tubes 33, 33 are fixedly protruded from the inside of the seat frame 2. They are arranged concentrically and a pivot pin 23 is inserted and pivotally supported. and the pivot pin 2
A pine needle pin 34 is inserted to prevent the part 3 from coming off.

(F) Effects of the Invention Since the present invention is configured as described above, it has the following effects.

First, as the seat lowers, the cross pin 7 that connects the pivot parts of the left and right cross links is brought into contact with the outer surface of the seat spring 6, and the seat spring is bent and expanded. It exhibits spring characteristics that are soft for small loads and hard for large loads, so even if a small and weak spring is used in a narrow space, it can support large loads.

Furthermore, the seat spring 6 is not bent during the initial descent of the seat 1, but only extends. Then, at the final stage of the lowering of the seat 1, the seat spring 6 begins to bend and expand for the first time.

In this way, the seat spring 6 of the present invention is
The spring coefficient differs depending on whether the seat spring 6 is only extended halfway or if it is bent and expanded halfway, and this allows the seat spring 6 to act as both a soft spring and a hard spring.

Second, the rotating arms 12 and 13 that pivot the lower ends of the cross links 3 and 4 are mounted on a bearing ring 3 on a slide guide 17 for sliding the seat back and forth.
0 and 42 are fixed and supported, the cross links 3 and 4 can take the left and right span depending on the width of the slide guide 17, making the support width wider than before and increasing the support strength. It was possible to do that.

In addition, the slide guide 17 and the cross link 3,
4 and the seat 1 as an assembly can be moved back and forth on the slide rail 19, so it can be adjusted according to the physique of the operator.

Thirdly, the rotating arm rotates downward and comes into contact with and locks with the upper surface of the slide guide.
Since it also serves as the stopper on the lowering side of the seat,
It acts as a stopper when a strong impact from the work equipment is applied when driving on rough roads or uneven terrain, and prevents other parts of the seat suspension system from being destroyed. In addition, since the rotary arm and stopper could be used together, it was possible to reduce the number of parts and reduce costs.

[Brief explanation of drawings]

FIG. 1 is a side view of the seat suspension device of the present invention, FIG. 2 is a partial front sectional view, FIG. 3 is a rear view, and FIG. 4 is a drawing showing the spring curve of the seat spring of the present invention. . 1... Seat, 2... Seat frame, 3, 4
...Cross link, 5 ... Tuning link, 6 ... Seat spring, 7 ... Cross pin, 12 ... Rotating arm, 17 ... Slide guide, 30 ... Bearing ring.

Claims (1)

[Claims] 1. Cross links 3, 4 whose front and rear centers are supported by cross pins 7 are arranged on the left and right, and the seat 1 is supported by the left and right cross links 3, 4. A seat spring 6 is disposed between the front and rear ends of cross links 3 and 4 that open and close back and forth as the seat 1 descends and rises, and the seat spring 6 expands and contracts as the seat 1 descends and rises to absorb shock. The cross pin 7 that pivotally supports the cross links 3 and 4 is lowered, and the cross pin 7 comes into contact with the longitudinal center of the seat spring 6, so that the seat spring 6, which has expanded due to the lowering of the seat 1, is further bent and expanded. A seat suspension structure characterized by the following structure. 2. In the cross links 3, 4 according to claim 1, the rotating arm shafts 1 of the rotating arms 12, 13 that pivotally support the lower ends of the cross links 3, 4.
4 and 15 are pivotally supported by bearing rings 30 and 42 fixed on a slide guide 17 for slidingly adjusting the entire seat device back and forth. 3 Rotating arm 1 according to claim 2
2 and 13 rotate downward and slide guide 1
By contacting and locking the upper surface of sheet 7, sheet 1
A seat suspension structure comprising a stopper on the descending side of the seat.