JPS625940Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a column shift device for a tractor that performs a gear shift operation near the steering wheel.

In general, agricultural tractors have a large number of gears for adjusting the traveling speed, and are provided with a plurality of gear shift levers such as a main gear lever and a sub-shift lever. These shift levers are each operated by separate operation levers. Therefore, there is a so-called column shift device in which an operating lever, which is operated most frequently during work, is disposed near a steering wheel in order to facilitate gear shifting operations. This operation is generally performed by sliding the control lever up and down to perform a selection operation, and by rotating the control lever back and forth to perform a shift operation. Among such column shift devices, those in which the select operation is performed in three stages of upper, middle, and lower stages make it difficult to shift in the middle position unless the operating lever is reliably positioned in the middle position during the select operation. That is, for the upper and lower stages, the operating lever can be easily positioned at the upper or lower shift operating position by pulling up or pushing down to the position where it hits the stopper, respectively, but it is not possible to position the operating lever at the middle shift operating position. If the operating lever is deviated from the shift operation position, the shift lever inside the transmission case and the shifter boss will not engage, making it impossible to perform the shift operation. Moreover, this operating lever is different from the one used in general automobiles, which sequentially shifts gears from low to high speed or vice versa, and is operated frequently depending on the type of work and changes in load, and is used to switch between forward and backward movement. is also done frequently. For this reason, the neutral position, which serves as a guide for gear shifting and switching operations, must be particularly clear.

This idea was developed in view of these points, and it is a tractor column that allows the operating lever to be reliably positioned at the middle gear shift operation position when performing a select operation, and also makes it possible to clearly identify the neutral position of each gear. The purpose is to obtain a shift device.

In this invention, a control shaft with an operating lever is provided in parallel with the steering column so that it can move up and down in the direction of its axis and can rotate around its axis, and is biased upward by a spring and the control shaft is A movable body that can move up and down along the axis supports the protrusion protruding from the control shaft from below, and the highest position of the movable body is restricted by a stopper, so that the movable body is biased by the spring. The position of the control shaft, which is supported by the protrusion and fixed in position by this movable body when it is in the highest position, is defined as the middle gear shift operation position, and the predetermined position where the operating lever is pulled up from that position is defined as the upper gear shift operation position. Furthermore, a predetermined position where the operating lever is pushed down while resisting the biasing force of the spring is defined as the lower shift operating position, and the control shaft is rotated about its axis to shift the protrusion. The operating lever is configured to be positioned at a neutral position by engaging with the locking recess of the movable body.

An embodiment of this invention will be described based on the drawings. The tractor body 1 has a steering column 2.
In parallel with this, a control shaft 3 is provided so as to be movable up and down along its axis and rotatable around the axis. An operating lever 4 is bent sideways at the upper end of the control shaft 3, and a boss 6 of a shift arm 5 is fixed to the lower end by a pin 7. A bent portion 11 at the other end of an arm 10 to which a cylinder 9 is fixed at one end is held. The cylindrical body 9 has a shift rod 1 connected at one end to a gear shift lever (not shown) in the transmission case 12.
The other end of 3 is inserted and fixed. Further, a groove portion 14 is formed in the cylindrical body 9, and an engaging portion 15 of the shift arm 5 is engaged with this groove portion 14. The shift rod 13 has a horizontal axis parallel to the longitudinal direction of the body 1, and is provided so as to be slidable in the direction of the axis and freely rotatable around the axis.

Therefore, the control shaft 3 is connected to the stopper 1 fixed to the steering gear case 16.
7 is inserted. Further, a metal fitting 20, which is a movable body and has a facing plate 18 located above the stop 17 and a facing plate 19 located below the stopper 17, is inserted into the control shaft 3 so as to be slidable in the vertical direction. There is. Further, the control shaft 3 is provided with the stopper 17.
A spring 21 is inserted between the metal fitting 20 and the opposing plate 18 while urging the metal fitting 20 upward. A pin 22, which is a protrusion projecting laterally, is fixed to the control shaft 3, and a locking recess 23 that elastically engages with the pin 22 is formed on the outer surface of the opposing plate 18. .

In such a configuration, a select operation is performed by moving the operating lever 4 up and down along the axis of the control shaft 3, and a shift operation is performed by rotating the operating lever 4 around the axis of the control shaft 3. It is done. That is, when the operating lever 4 and the control shaft 3 are moved up and down from the state shown in FIG. 2 as shown in FIG. 4 or FIG.
moves up and down together with the operating lever 4 while holding the bent portion 11 of the arm 10, and rotates the arm 10 upward or downward about the axis of the shift rod 13. The shift rod 13 is rotated by the rotation of the arm 10.
The transmission case 12 rotates around its axis.
In this step, the gear shift lever selectively engages with any one of the shifter bosses (not shown), and a selection operation is performed in this manner. Further, when the operating lever 4 is rotated around the axis of the control shaft 3, the shift arm 5 is rotated in a horizontal plane about the boss portion 6, and the engaging portion 15 of the shift arm 5 is moved in the front-rear direction. Then, due to the engagement between the engaging portion 15 and the groove portion 14, the cylindrical portion 9 also moves in the front-rear direction. As a result, the shift rod 13 slides in its axial direction, and the shift lever drives the shifter boss to perform a shift operation.

Next, a mechanism for positioning the operating lever 4 at each of the upper, middle, and lower shift operation positions when moving the operating lever 4 up and down to perform a selection operation will be described. FIG. 2 shows a state in which the operating lever 4 is in the middle neutral position. That is, the metal fitting 20 is urged upward by the spring 21 and is located at the highest position where the opposing plate 19 is joined to the stopper 17. And the operation lever 4
The pin 22 is supported by the opposing plate 18.
Therefore, by determining the highest position of the metal fitting 20 as the middle shift operation position, the operating lever 4 can be accurately positioned at the middle shift operation position. Also, in the middle position, by rotating the operating lever 4 around the axis of the control shaft 3, the pin 22 engages with the locking recess 23, and the feeling of the pin 22 falling into the locking recess 23 causes the operating lever 4 to rotate. can reliably perceive that it is located at a neutral position.

Next, in order to position the operating lever 4 to the upper shift operating position, the operating lever 4 is pulled up in the axial direction of the control shaft 3. As shown in FIG. 4, the operating lever 4 has a boss 6 that is connected to the opposing plate
9, and by rotating the operating lever 4 about the axis of the control shaft 3 at that position, a shift operation in the upper position can be performed. Further, this shift operation position is the maximum raised position of the operation lever 4 and can be reliably perceived. In addition, in the upper shift operation position,
Although the pin 22 separates from the opposing plate 18, when it returns to the neutral position by rotating the insertion lever 4, it falls to the middle position due to its own weight, so there is no problem with the shift operation.

Next, when positioning the operating lever 4 to the lower shift operating position, the operating lever 4 is pushed down against the biasing force of the spring 21, and the fifth
The figure shows the state in which it is pushed down to the lower neutral position. That is, the metal fitting 20 is pushed by the pin 22 and moves downward together with the operating lever 4 and the control shaft 3, and the spring 21 is compressed by the stopper 17 and the opposing plate 18. Then, when the operating lever 4 is at the maximum lowered position,
Shift operation to the lower position can be performed by rotating. Note that when the user releases the operating lever 4 at the lower neutral position, the operating lever 4 is automatically returned to the middle neutral position due to the biasing force of the spring 21.

In this device, a movable body urged upward by a spring supports a protrusion protruding from the control shaft from below, the highest position of the movable body is regulated by a stopper, and the highest position is moved to the middle stage. By determining the shift operation position as the middle shift operation position, the operation lever can be reliably positioned at the middle shift operation position, and the locking recess formed on the movable body and the protrusion can be elastically engaged. This allows you to reliably position the upper, middle, and
This has the advantage that the column shift device having the shift operation position in the lower stage can smoothly perform the gear change operation.

[Brief explanation of the drawing]

The drawing shows one embodiment of this invention.
The figure is a side view showing the whole on a reduced scale, Figure 2 is a rear view showing the main parts with the operating lever in the middle neutral position, Figure 3 is a plan view, and Figure 4 is a rear view showing the main parts.
The figure is a rear view with the operating lever in the upper neutral position, and FIG. 5 is the rear view with the operating lever in the lower neutral position. 2...Steering column, 3...Control shaft, 4...Operation lever, 17...Stopper, 20...Metal fitting (movable body), 21...Spring, 22...Pin (protrusion), 23...Register Stop recess.

Claims (1)

[Scope of utility model registration request] A control shaft is installed near the steering column, with an operating lever on the top, and a control shaft that defines vertical movement along the axis as a select movement, and movement from the neutral position to the left and right around the axis as a shift movement. A movable body that supports from below a protrusion projecting laterally from the outer periphery of the control shaft while being biased upward by a spring is provided so as to be movable up and down along the axis of the control shaft, and the movable body The raised position is determined by a stopper so that the movable body is interlocked only with the movement of the control shaft from the middle position to the lower position, and a locking recess that elastically engages with the protrusion is provided in the neutral position of the control shaft. A column shift device for a tractor, characterized in that the column shift device is formed on the movable body and positioned on a radius around the axis of the control shaft.