JPH04107348A - Speed change mechanism for tractor - Google Patents

Abstract

PURPOSE:To eliminate a main clutch and to reduce size by arranging an auxiliary transmission between a prime mover and a main transmission and coupling the output shaft of the prime mover directly to the input shaft of a transmission. CONSTITUTION:A clutch type auxiliary transmission II is arranged to the rear half of a conventional clutch housing H, and a transmission case M is arranged on the rear surface of the clutch housing H. Namely, the auxiliary transmission II is arranged between a prime mover I and a main transmission III. A main clutch is eliminated and a power is directly transmitted to a transmission input shaft 11 from the crank shaft of the prime mover I. The main transmission III and an auxiliary transmission IV are arranged at the interior of the transmission case M arranged in a joined state to the rear surface of the clutch housing H. This constitution eliminates a need to arrange a mechanical type main clutch like a conventional tractor and sharply reduces both the longitudinal size and the size in the direction of the width of the transmission case.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a tractor transmission mechanism, and particularly to a clutch-type auxiliary transmission device disposed between a prime mover and a main transmission device.

(B) Prior Art Conventionally, a technique in which a clutch-type auxiliary transmission is disposed between a prime mover and a main transmission has been known.

For example, Tokukai Showa 5! This is similar to the technology described in >6453.

(C) Problems to be Solved by the Invention However, in the above-mentioned conventional technology, an auxiliary transmission device is arranged, but the clutch that makes up the auxiliary transmission device is always in a disengaged state and is engaged only when power is transmitted. Therefore, a large mechanical main clutch is disposed between the auxiliary transmission and the prime mover to transmit power.

In the present invention, since both the main clutch and the clutch type auxiliary transmission device are clutches, the main clutch is omitted by using them for both purposes.

(d) Means for Solving the Problems The problems to be solved by the present invention are as described above. Next, the means for solving the problems will be explained.

It consists of a prime mover ■, a main transmission ■, an auxiliary transmission ■, and an auxiliary transmission ■.The auxiliary transmission ■ is placed between the prime mover ■ and the main transmission ■, and the output shaft of the prime mover I and the transmission input It is directly connected to the shaft 11.

In addition, it is composed of a prime mover ■, a main transmission ■, an auxiliary transmission ■, and an auxiliary transmission ■, and the auxiliary transmission ■ is placed between the prime mover ■ and the main transmission ■, and the auxiliary transmission ■ is a clutch type. The transmission is a transmission having a plurality of forward gear positions and a reverse gear position.

Further, the gear ratio of the forward low-speed clutch FL and the gear ratio of the reverse clutch R are set to be substantially the same gear ratio.

Further, the forward speed change clutch is always in an engaged state and is in a disengaged state by pressure oil supply from a control valve, and an auxiliary supply oil passage 6 is provided in parallel with the main supply oil passage 5 for pressure oil.

Further, the forward low-speed clutch FL, the forward high-speed clutch FH, and the reverse clutch R are operated via electromagnetic proportional valves ■1, ■2, and ■3, and a human operating tool 7 is provided. The operating position sensor 1 is linked to the electromagnetic proportional valves V1, 2, and 3.

(P) Embodiment The problems to be solved by the present invention and the means for solving the problems are as described above.Next, the structure of the embodiment shown in the attached drawings will be explained.

Fig. 1 is a hydraulic circuit diagram of the transmission mechanism of a tractor according to the present invention, Fig. 2 is an electronic control circuit diagram, and Fig. 3 is an auxiliary transmission device H.
FIG.

First, explanation will be given starting from FIG.

The clutch-type auxiliary transmission device (2) of the present invention is disposed in the latter half of a conventional clutch housing H, and a transmission case M is disposed on the rear surface of the clutch housing H.

The clutch housing H is attached to the rear surface of the prime mover I, and a main clutch has conventionally been disposed at the joint between the prime mover I and the clutch housing H. However, in the present invention, the main clutch is eliminated, and power is transmitted directly from the crankshaft of the prime mover (2) to the transmission input shaft 11.

A main transmission device (2) and a sub-transmission device (2) are arranged inside a transmission case M that is connected to the rear surface of the clutch housing H.

The main transmission device (2) and the sub-transmission device (2) are configured as a gear sliding type transmission device.

Further, the direction of power transmission from the transmission input shaft 11 is divided into two parts: traveling power and PTO power, and the traveling power is transmitted from the transmission input shaft 11 to the cylinder shaft 9 on the outer periphery, and from the cylinder shaft 9. Power is transmitted from the gear 16 to the transmission cylinder shaft 8 by selectively engaging the forward high-speed clutch FH, the forward low-speed clutch FL, and the reverse clutch R. A main transmission device (2) and a sub-transmission device (2) are constructed between the transmission cylinder shaft 8 and the counter shaft 13.

For the PTO power transmission mechanism, from the transmission input shaft 11 to the PT
Power is directly transmitted to the O power transmission shaft 12, and as shown in FIG. 1, a PTO clutch T is disposed at the rear of the PTO power transmission shaft 12.

Between the power transmission system from the transmission input shaft 11 to the transmission cylinder shaft 8, three systems are interposed in parallel: a forward high speed clutch FH, a forward low speed clutch FL, and a reverse clutch R.
By selectively engaging the three clutches, three auxiliary gears for forward high/low and reverse are performed.

The forward high speed is transmitted to the transmission input shaft 11, the middle cylinder shaft 9, the forward high speed clutch FH, the gear 16, and the transmission cylinder shaft 8.

Low forward speed is controlled by transmission input shaft 11-0 cylinder shaft 9Q gear 13
) Gear 18-O forward low speed clutch FL → counter shaft 14 = + gear 17) gear 16 -> transmission cylinder shaft 8.

The reverse gear is transmitted through the transmission input shaft 11, cylinder shaft 9 → gear 15 < gear 19-=O reverse clutch R-) counter shaft 14 → gear 17 ==) gear 16 and transmission cylinder shaft 8. .

In order to eliminate the main clutch, the present invention maintains either the forward low-speed clutch FL or the forward high-speed clutch FH in a normally engaged state, and when the other clutch is engaged, the forward clutch in the normally engaged state is This causes the clutch to disengage.

Next, this will be explained with reference to FIG.

In conventional tractors, an artificial operating tool 7 with a shape similar to a clutch pedal is used as a substitute operating tool to replace the clutch pedal that is depressed to disconnect the main clutch.
are placed. The human operating tool 7 has the shape of a clutch pedal, and the operating intervals are the same, but in reality, it only rotates the operating position sensor 1, which is a small electronic component.

In order to eliminate the discomfort with the conventional operation feeling,
A human operating tool 7 is provided as a substitute for operation.

The forward/reverse switch 2 and height/low switch 3 are located on the dash board, so first select either forward or backward with the forward/reverse switch 2, then select either high/low with the height/low switch 3. .

By this operation, the solenoid 5oil, soρ2, s of the electromagnetic proportional valve ■1, ■2, V3 is activated via the controller C.
One of og3 is excited.

The electromagnetic proportional valves ■1, ■2, and ■3 are the human operating tools 7.
The operating position sensor 1 detects the position depending on the degree of stepping on the pedal, and the excitation state of the solenoids SOβ1, SOβ2, and SOβ3 is changed via the controller C based on the detected value.

As a result, the engagement strength of the forward high-speed clutch FH, the forward low-speed clutch FL, and the reverse clutch R changes, and a half-clutch state is obtained.

In addition, in controller C, if the battery terminal is disconnected,
Forward high-speed clutch FH that is always engaged when a de-energized state occurs due to a failure in other electric circuits.
If the valve is not released, an accident may occur, so an emergency valve V6 is provided. The emergency solenoid soβ4 operates the emergency valve 6 to the disengagement side of the forward high speed clutch FH.

Next, referring to FIG. 1, the overall hydraulic circuit configuration will be explained.

A hydraulic pump P1 for speed change operation and a hydraulic pump P2 for other working machines are connected to the prime mover (2), and the hydraulic pump P2 for other working machines is mainly used for power steering of the tractor.

In addition to the three hydraulic clutches of the auxiliary transmission device (■) of the present invention, the hydraulic pump P1 for speed change operation includes a PTO clutch T, a four-wheel drive clutch W, and a double-speed pump that facilitates headland turning in rice fields. Pressure oil is also supplied to the swing clutch G.

The four-wheel drive clutch W and the double speed swing clutch G are operated by a switching valve V7.

The PTO clutch T is operated by a PTO control valve 4, and in addition to the engagement and disengagement of the PTO clutch T by the PT and O control valve V4, an inertial rotation braking brake B1 that operates when the PTO clutch T is disengaged and a PTO When the clutch T is engaged, the detent pressing mechanism B2 is operated, which disables the speed change operation by the sliding gear of PT○.

A relief valve L2 is disposed in a circuit in which the main supply oil passage 5 from the hydraulic pump P1 for speed change operation supplies pressure oil to the switching valve ■7, and the relief valve L2 has a diameter of about 17 cm.
It is set to kg/cut.

Therefore, priority is given to the operation of the auxiliary transmission H, and hydraulic pressure when it is not necessary is supplied to the double speed swing clutch G and the four-wheel drive clutch W from the switching valve V7 via the relief valve L2.

In addition, a main supply oil path 5 from the hydraulic pump P1 for speed change operation,
A switching valve V5 is arranged at the confluence of the circuits of the auxiliary supply oil passage 6 from the hydraulic pump P2 for other working machines, and when there is pressure in the main supply oil passage 50 circuit, the switching valve V5
This is configured to give priority to this, and when pressure does not build up on the side of the main supply oil path 5, the pressure oil discharged from the auxiliary supply oil path 6 via the relief valve L1 is transferred to the relief valve [
, 3.

The set pressure of relief valve L1 is approximately 5 kg/cf, and the set pressure of relief valve L3 is 17 kg/cm.
It is set to l.

Next, the pressure oil supplied from the main supply oil passage 5 or the auxiliary supply oil passage 6 is supplied to the forward high speed clutch FH, the forward low speed clutch FL, and the reverse clutch R via the electromagnetic proportional valves V1, ■2, and ■3. However, in the embodiment shown in FIG. 1, the forward high-speed clutch FH is always engaged, and when the other forward low-speed clutch FL and reverse clutch R are engaged, it is disengaged. It is configured.

An emergency valve V6 is disposed in the circuit of the forward high-speed clutch FH, and when the controller C detects a failure in the electric circuit, the emergency solenoid 5oj24 is energized and switches the emergency valve V6. The forward high-speed clutch FH, which is always engaged, is also disconnected.

The forward low-speed clutch FL and the reverse clutch R are always in a disengaged state, and are only engaged when the forward/reverse switch 2 or the elevation switch 3 is operated.

K is a key switch.

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

As claimed in claim (1), the motor is composed of a prime mover (■), a main transmission (■), an auxiliary transmission (■), and an auxiliary transmission (■), and the auxiliary transmission (■) is disposed between the prime mover (■) and the main transmission (■), I
Since the output shaft of the transmission case and the transmission input shaft 11 are directly connected, there is no need to dispose a mechanical main clutch like in conventional tractors, so the transmission case can be configured to be significantly smaller in both the front and rear dimensions and the width direction. It was possible.

For the same reason, costs can be reduced.

Also, there is no need to operate the main clutch as in the past.

As claimed in claim (2), it is composed of a prime mover I, a main transmission ■, an auxiliary transmission ■, and an auxiliary transmission ■, and the auxiliary transmission ■ is disposed between the prime mover ■ and the main transmission ■, and the auxiliary transmission Since the transmission device (■) is a clutch-type transmission and has multiple stages of forward shift positions and reverse shift positions, when high-speed, low-torque driving is required, the forward high-speed clutch FH is used to shift the forward high-speed clutch FH to the low-speed, high-torque state. In this state, the low forward speed clutch FL can be engaged and selectively engaged for different purposes, and the low forward speed clutch FL and the high speed forward clutch FH can also be switched automatically.

In addition, by alternately engaging the forward low-speed clutch FL and the reverse clutch R, operation becomes easier in front loader work where work is performed while moving forward and backward, such as in a front rogue.

It also makes it easier to move around the headland.

In addition, even if a highly reliable mechanical transmission is used as the main transmission (■) or the auxiliary transmission (■), and the shift lever is used to shift the gear while the power is cut off, the clutch will cut off the power at the auxiliary transmission (■). This allows you to change gears without any manual operation.

As claimed in claim (3), the gear ratio of the forward low-speed clutch FL and the gear ratio of the reverse clutch R are set to be substantially the same gear ratio, so that repeated forward and reverse operations can be performed safely, and operability at that time is also improved. improves.

According to claim (4), the forward speed change clutch is always in an engaged state and is in a disengaged state by supplying pressure oil from a control valve,
Since the auxiliary supply oil passage 6 is provided in parallel with the main pressure oil supply oil passage 5, even if the hydraulic pump P1 for gear shift operation breaks down,
Since pressure oil can be supplied via the auxiliary supply oil passage 6 by the hydraulic pump P2 for other working machines, the forward high speed clutch FH can be reliably disengaged.

As claimed in claim (5), the forward low-speed clutch FL, the forward high-speed clutch FH, and the reverse clutch R are connected to the electromagnetic proportional valve ■1.
■2 and ■3, an artificial operating tool 7 is provided, and the human operating tool 7 is equipped with an operating position sensor 1, and the operating position sensor 1 is linked to the electromagnetic proportional valves V1, ■2, and ■3. Therefore, the human operating tool 7 and the operating position sensor 1 have priority over the reverse switch 2 and the height/lower switch 3, so if an emergency situation occurs with the tractor, the human operating tool 7 and the operating position sensor 1 can stop the machine. This is possible.

Since the electromagnetic proportional valves V1, 2, and V3 are proportionally controlled by the human operating tool 7, there is no sudden start of the tractor body.

[Brief explanation of drawings]

Fig. 1 is a hydraulic circuit diagram of the transmission mechanism of the tractor of the present invention, Fig. 2 is an electronic control circuit diagram, and Fig. 3 is an auxiliary transmission system.
FIG. 1 ・ ・ 2 ・ ・ 3 ・ ・ FH, FL ・ R Sub-transmission device Applicant Yanmar Diesel Co., Ltd. Agent Patent attorney Hisashi Yano Part

Claims (5)

[Claims] (1) Consists of a prime mover, a main transmission, an auxiliary transmission, and an auxiliary transmission.The auxiliary transmission is placed between the prime mover and the main transmission, and the output shaft of the prime mover is directly connected to the input shaft of the transmission. A tractor transmission mechanism characterized by: (2) Consisting of a prime mover, a main transmission, an auxiliary transmission, and an auxiliary transmission, the auxiliary transmission is disposed between the prime mover and the main transmission, and the auxiliary transmission is a clutch type transmission, A tractor transmission mechanism characterized by having a plurality of forward speed change positions and a reverse speed change position. (3) The tractor transmission mechanism according to claim (2), wherein the transmission ratio of the forward low-speed clutch and the transmission ratio of the reverse clutch are substantially the same transmission ratio. (4) In the tractor transmission mechanism according to claim (1), the forward speed change clutch is always in an engaged state, and is in a disengaged state by pressure oil supply from a control valve, and an auxiliary transmission clutch is provided in parallel with the main pressure oil supply oil path. A tractor transmission mechanism characterized by having a supply oil passage. (5) In the tractor transmission mechanism according to claim (2), the forward low-speed clutch, the forward high-speed clutch, and the reverse clutch are actuated via electromagnetic proportional valves, and a human operating tool is provided, and the manual operating tool is located at an operating position. A tractor transmission mechanism characterized by being equipped with a sensor and having an operation position sensor and an electromagnetic proportional valve interlocked.