JPH0210864Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to a main transmission interlocking structure for agricultural tractors.

(b) Prior art Conventionally, as a type of main transmission interlocking structure, a rotary boss for interlocking the main transmission gear is loosely fitted into a support boss, and an interlocking shaft having a main transmission lever is slid left and right on the rotary boss. There is a structure in which an engaging rod is inserted and supported so as to be movable and rotatable, and an engaging rod that can be freely inserted and removed from an interlocking plate connected to a rotation boss is connected to an interlocking shaft. It was difficult to install a lock structure to lock the left and right sliding and rotation of the shaft, and it did not have a sufficient locking function.

(c) Problems to be solved by the invention Therefore, even when the interlocking shaft is slid left and right to change the main transmission gear, the rotation of the interlocking shaft and the rotation of the rotary boss are free, and the engagement rod and rotation are free. It was difficult to perform a reliable gear shifting operation because the boss's interlocking plate and the boss were misaligned.

(d) Means for solving the problem In the present invention, an engagement recess and a guide hole are provided in the support boss and the rotation boss at corresponding positions, respectively, and the lock pin is inserted between the recess and the hole. By forming an engagement groove in the interlocking shaft, when the engagement groove moves to the lock pin position, the lock pin is removed from the engagement recess and becomes the guide hole. It is an object of the present invention to provide a main speed change interlocking structure for an agricultural tractor, which is configured to be displaced so as to straddle the engagement groove, so that a reliable main speed change operation can be performed while having a simple structure.

(E) Effect According to the present invention, when the lock pin is housed across the guide hole and the engagement recess, the rotation boss is fixed to the support boss and the rotation boss is inserted into the interlocking plate of the rotation boss. The rotation of the interlocking shaft is reliably locked through the inserted engagement rod, so there is no risk of erroneous operation.

In addition, when the engagement groove moves to the lock pin position, the lock pin is displaced to straddle the guide hole and the engagement groove, so the left and right sliding of the interlocking shaft is stopped by the lock pin, and the rotation boss is fixed to the support boss. Since the interlocking shaft and the rotary boss rotate together through the engagement rod, the main transmission gear can be reliably switched.

(f) Effects Since the present invention is constructed as described above, the left and right sliding and rotation of the interlocking shaft can be reliably locked by sharing the lock pin, and although the structure is simple,
The main gear shifting operation can be performed reliably, there is no fear of erroneous operation, and safety can be ensured.

(G) Example The example of the present invention will be explained in detail based on the drawings.
A shows an agricultural tractor, and this agricultural tractor A has a bonnet 2 in which a prime mover 1 is housed in the front part of a machine body a, a steering handle 3 in the rear part of the bonnet 2, and a steering wheel 3 in the rear part of the machine body a. A transmission case 4 is disposed, a driver seat 6 is supported on the case 4 via a seat support 5, a main gear shift lever 7 is protruded from the left side of the driver seat 6, and the aircraft a
A front wheel 8 and a rear wheel 9 are arranged on both sides of the front and rear wheels, respectively, and the front and rear wheels 8 and 9 are driven by the power of the prime mover 1 to drive the vehicle, and the speed of the vehicle can be changed by operating the main shift lever 7. This is what we do.

Here, the main shift interlocking structure M, which mainly includes the main shift lever 7, will be explained as follows.

That is, the left and right stays 1 are placed on the lower side of the seat support base 5.
The left and right support bosses 11 and 11' are connected and fixed at a constant distance from each other via pins 0 and 10'. In addition, left and right rotation bosses 1 are provided in the same left and right support bosses 11 and 11'.
2 and 12' are rotatably supported with a loose fit while maintaining a certain distance from each other, and the left and right rotation bosses 12 and 1
A 2nd and 4th speed interlocking plate 13 and a 1st and 3rd speed interlocking plate 13' are respectively provided vertically at the inner end of 2', and both sides of the interlocking shaft 14 are inserted and supported in the left and right rotation bosses 12 and 12'. The shaft 14 is horizontally supported so as to be slidable left and right and rotatable. A longitudinal shift stay 15 is inserted and supported in the center of the interlocking shaft 14, and the main shift lever 7 is connected to the upper end of the stay 15 in a protruding state, and the interlocking plate 13 is connected to the lower end of the stay 15. , 13 to be engaged with the engaging rod 16
The center portion is inserted and supported, and both ends of the engaging rod 16 protrude to the left and right sides of the stay 15. That is, both ends of the engagement rod 16 are connected to the interlocking plates 13, 1.
It is constructed so that it can be removably engaged with engagement holes 17 and 17' provided at the lower end portion of 3'.

Further, the upper parts of the interlocking plates 13, 13' are provided with protruding parts 18 at the front, and each protruding part 18 has a 2nd and 4th speed gear,
Interlocking rod 1 for interlocking the 1st and 3rd gears respectively
A link mechanism 21 is constructed by connecting the upper ends of the interlocking rods 19 and 19', and interlockingly connecting interlocking plates 20 and 20', which are to interlock the transmission fork shafts of the respective gears, to the lower ends of the interlocking rods 19 and 19'.

In addition, left and right guide holes 22 and 22' are bored on the upper circumferential side of the left and right rotation bosses 12 and 12'.
At least the same guide holes 22, 2 are provided in 2, 22'.
Left and right locking pins 2 in the shape of a vertical column with a longer diameter than 2'
The lock pins 23 and 23' are housed in a vertically slidable manner, and the upper and lower ends of the lock pins 23 and 23' are each formed into a semicircular arc shape.

In addition, at the left and right midway positions of the interlocking shaft 14,
Engagement grooves 24 and 24' having a semicircular cross section to engage with the lower end surfaces of the lock pins 23 and 23' are provided around the circumference, and the sliding shaft 14 is slid left and right by the main shift lever 7. The left and right ends are left and right engagement holes 17,1
7' respectively to interlock 2nd and 4th speeds, 1st and 3rd gears.
When the left lock pin 2 is positioned so that the speed can be linked, the left engagement groove 24 faces the left guide hole 22.
3, the tip engages with the left engagement groove 24, or the right engagement groove 24' faces the right guide hole 22', and the right lock pin 23' engages with the right engagement groove 24', and the interlocking shaft 1
The left and right sliding movement of No. 4 is configured to be locked.

In addition, left and right engagement recesses 25 and 25', which are to be engaged with the upper end surfaces of left and right lock pins 23 and 23', are provided on the upper inner circumferential surfaces of the left and right support bosses 11 and 11', facing the left and right guide holes 22 and 22'. When the left and right engagement grooves 24, 24' of the interlocking shaft 14 are not opposed to the left and right guide holes 22, 22', the left and right lock pins 23, 23' are supported by the circumferential side of the interlocking shaft 14, and the left and right lock pins are locked. The upper ends of 23 and 23' engage with the left and right engaging recesses 25 and 25', and the lock pin 2
3, 23' are the guide holes 22, 22' and the engagement recess 2.
It is configured so that it can be stored across 5 and 25'. In addition, the left and right engagement grooves 2 of the interlocking shaft 14
4, 24' are opposed to the left and right guide holes 22, 22', the left and right lock pins 23, 23' slide downward and the lower ends engage the left and right engagement grooves 24, 24' as described above, and the left and right lock pins 23 , 23' upper ends are separated from the left and right engagement recesses 25, 25', and the left and right lock pins 23, 23' are configured to span the guide holes 22, 22' and the engagement grooves 24, 24'.

The main gear shift of the main gear shift lever 7 is H-type, with the left front and rear being 4th and 2nd gear, respectively, the right front and rear being 3rd and 1st gear, respectively, and a concave neutral shifter at the center right end of the left side. 26, and a pressing spring 27 interposed between the right rotation boss 12' and the shift stay 15 pushes the main shift lever 7.
energizes the neutral shift 26.

The embodiment of the present invention is constructed as described above, and the main shift lever 7 is connected to the biasing spring 2.
7, the right side of the engagement rod 16 engages with the engagement hole 17', and the right engagement groove 24' faces the right guide hole 22'. In this state, the right lock pin 23' slides downward under its own weight, and the upper end of the pin 23' separates from the right fitting recess, and the lower end of the pin 23' engages with the right engagement groove 24', and the interlocking shaft 14 In this state, if the main shift lever 7 is rotated back and forth through the back and forth rotation of the interlocking shaft 14, the gears will be shifted to 1st speed and 3rd speed.

Furthermore, if the main shift lever 7 is slid to the right together with the interlocking shaft 14 against the locking of the right lock pin 23', the lower end of the right lock pin 23' will move into the right engagement groove 2.
4' movement, it is pushed up and the right lock pin 2
3' is supported on the peripheral side of the interlocking shaft 14, so that the interlocking shaft 14 can slide without any trouble. In this state, the main shift lever 7 slides to the left together with the sliding shaft 14 due to the biasing force of the pressing spring 27, and when the left engagement groove 24 faces the left guide hole 22, the left lock pin 23 is moved by its own weight. As the pin 23 slides downward, the upper end of the pin 23 separates from the left engagement recess 25, and the lower end of the pin 23 engages with the left engagement groove 24, thereby locking the left sliding movement of the interlocking shaft 14.
In the same state, if the main shift lever 7 is rotated back and forth through the forward and backward rotation of the interlocking shaft 14, the gears will be shifted to the second and third speeds.

Furthermore, if the main shift lever 7 is slid to the left together with the interlocking shaft 14 against the locking of the left lock pin 23, the main shift lever 7 moves with the left lock pin 23 pushed up, and the biasing force of the pressing spring 27 In response, the main shift lever 7 is held locked to the neutral shift 26.

In addition, except for the main gear shifting position where the lower ends of the left and right lock pins 23, 23' do not engage with the left and right engagement grooves 24, 24', the upper ends of the left and right lock pins 23, 23' engage with the left and right engagement recesses 25, 25'. The left and right rotation bosses 12 and 12' are connected to the left and right lock pins 23 and 2.
The rotation is locked through 3', and
Since the end of the engagement rod 16 is engaged with either the left or right engagement holes 17, 17', the forward and backward rotation of the main shift lever 7 is locked, preventing the main shift operation from occurring. There is.

[Brief explanation of drawings]

Fig. 1 is an overall side view of the embodiment of the present invention, Fig. 2 is a longitudinal cross-sectional view of the same main part, Fig. 3 is a longitudinal cross-sectional side view of the main part,
FIG. 4 is an explanatory diagram of the shift position. A: Agricultural tractor, 6: Driver seat, 7: Main gear shift lever, 12, 12': Left and right rotation boss, 14: Interlocking shaft, 21: Link mechanism, 22, 22':
Left and right guide holes, 23, 23': Left and right lock pins,
24, 24': Left and right engagement grooves, 25, 25': Left and right engagement recesses.

Claims (1)

[Scope of utility model registration request] Support bosses 11, 11' are fixed at a constant interval to the lower side of the driver's seat 6.
Link mechanism 2 for interlocking the main transmission gear with 1'
1 are interlocked and connected, respectively, and an interlocking shaft 14 having a main gear shift lever 7 is fitted and supported on the rotary bosses 12, 12' so as to be slidable left and right and rotatable. , rotating boss 1
Interlocking plates 1 are connected to each other in a protruding manner at 2 and 12'.
3 and 13', an engaging rod 16 that can be freely inserted and removed is installed in a state connected to the interlocking shaft 14, and a rotating boss 12 that is loosely fitted into the inner peripheral surface of the support boss 11, 11' and the same boss 11, 11'. , 12', and the engaging recesses 25, 25' and the guide holes 22,
22' is provided protrudingly, and the lock pin 2
3 and 23', as well as interlocking shafts 1 and 23'.
By forming the engagement grooves 24, 24' at appropriate positions on the four circumferential surfaces, the engagement grooves 24, 24' of the shaft 14 are moved to the lock pin 23, 23' positions in response to the sliding movement of the interlocking shaft. At this time, the lock pins 23, 23' are removed from the engagement recesses 25, 25' and are displaced to a state spanning the guide holes 22, 22' and the engagement grooves 24, 24'. Main transmission interlocking structure.