JPH0475419B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention comprises a manually-switchable main transmission connected to an engine via a transmission clutch, and an auxiliary transmission equipped with a two-stage high-low transmission system connected in series with the main transmission. The present invention relates to a control device for a vehicle transmission in which the sub-transmission is automatically switched in accordance with the throttle opening of the engine and the vehicle speed.

Conventionally, in this type of vehicle transmission, when the transmission clutch is released and the main transmission is shifted, and then the transmission clutch is reconnected, the high-speed transmission system of the auxiliary transmission may not be established depending on the driving condition. When the accelerator pedal is subsequently depressed, the gear stage of the auxiliary transmission may be downshifted from the high-speed transmission system to the low-speed transmission system, which is undesirable from the viewpoint of ride comfort and acceleration. This is accompanied by inconveniences such as a shift shock caused by the downshift after the shift, and a delay in acceleration due to the delay in the downshift.

It is an object of the present invention to provide a device that eliminates such inconveniences, and includes a manual main transmission connected to the engine via a transmission clutch, and a two-stage high and low gear transmission connected in series to the main transmission. In a vehicle transmission comprising a sub-transmission connected to a transmission system, the sub-transmission is automatically switched according to the throttle opening of the engine and the vehicle speed. A low-speed transmission system holding device is provided that holds the gear position of the auxiliary transmission in the low-speed transmission system while the transmission clutch is released and until a predetermined period of time has elapsed after the transmission clutch is connected. do.

The predetermined time is set to a time sufficient for the throttle opening to enter a range for establishing a low-speed transmission system by depressing the accelerator pedal after the gear shift clutch is connected, for example, about 2 to 3 seconds; When depressing the accelerator pedal immediately after shifting the main transmission, the throttle opening has already entered the low-speed transmission system establishment range at the time when the low-speed transmission system holding device is released from operation after the predetermined period of time has elapsed. A downshift from a high-speed transmission system to a low-speed transmission system does not occur.

The present invention will be explained below with reference to the illustrated embodiments.

Referring to FIG. 1, 1 is an engine, 2 is a transmission clutch, 3 is a main transmission connected to the engine 1 via the transmission clutch 2, and 4 is a sub-transmission connected in series to the main transmission 3. The vehicle transmission as a whole is shown as a transmission in which power from the engine 1 is transmitted to the drive wheels 6 of the vehicle via the main and sub transmissions 3 and 4 and the differential gear 5.

The main transmission 3 has a forward gear train G1 of 1st to 4th speeds as a speed change gear mechanism between an input shaft 3a connected to the speed change clutch 2 and an output shaft 3b connected to the differential gear 5. , G2, G3, G4 and reverse gear train
GR is installed, and these are used for 1st-2nd speed shifting and 3rd-speed gear shifting linked to the change lever 7 in the vehicle interior as shown in Fig. 2.
It is composed of a manual changeover type transmission with four forward speeds and one reverse speed, which is selectively established by the switching operation of the first and second switching clutches 8, 9 for 4-speed shifting and the idle shift gear 10 for reverse. The number of gears is increased by connecting the auxiliary transmission 4, which is equipped with two high and low gear transmission systems GH and GL, to the input or output side of the transmission gear mechanism.

To explain this in more detail, in the illustrated example, the sleeve shaft 1 on the input side of the transmission gear mechanism is connected to the input shaft 3a.
1, and the sleeve shaft 11 and the input shaft 3a
and a hydraulic clutch 12 in the high-speed transmission system GH, and a one-way clutch 13 that allows over-rotation on the output side in the low-speed transmission system GL, The low-speed transmission system GL is established when the hydraulic clutch 12 is released, and the high-speed transmission system GH is established when the hydraulic clutch 12 is connected.More specifically, the input shaft 3a is moved rearward. The hydraulic clutch 12 extends and connects the sleeve shaft 11 and the input shaft 3a in a freely disconnectable and disconnectable manner. A fixed fixed gear 14 is disposed, and both gears 11a,
14, which pivotally supports an idle gear mechanism 15 that connects the
The one-way clutch 13 that allows over-rotation on the output side, that is, the interlocking gear 11a side, is intervened in the idle gear mechanism 15 to provide a high-speed transmission system from the input shaft 3a to the sleeve shaft 11 via the hydraulic clutch 12. GH and the fixed gear 1 from the input shaft 3a.
4→idle gear mechanism 15→interlocking gear 11a constitutes a low-speed transmission system GL leading to the sleeve shaft 11, and when the high-speed transmission system GH is established by connecting the hydraulic clutch 12, the one-way The actuation of the clutch 13 stops power transmission through the low-speed transmission system GL. In the illustrated example, the first gear train G1 and the reverse gear train GR are directly connected to the input shaft 3a, and the second to fourth gear trains G2,
G3 and G4 are connected to the sleeve shaft 11, and the auxiliary transmission 4 provides two high and low speeds for each gear, so that the overall speed can be changed to seven forward speeds and one reverse speed. Of course, it is also possible to connect the gear trains G1 and GR to the sleeve shaft 11 so that eight forward speeds and two reverse speeds can be performed.

As shown in FIG. 2, the hydraulic clutch 12 is connected and disconnected by a switching valve 18 interposed in an oil path that regulates the pressure of pressure oil from a hydraulic pump 16 with a regulator valve 17 and leads it to the hydraulic clutch 12. That is, the switching valve 18 can be freely switched between a refueling position where oil is supplied to the hydraulic clutch 12 and an oil drain position where oil is drained from the hydraulic clutch 12, and when the switching valve 18 is switched to the refueling position, the hydraulic clutch 12 is connected. This is released by switching to the oil drain position.

In order to automatically switch the auxiliary transmission 4 according to the throttle opening of the engine 1, the vehicle speed, and the gear stage of the main transmission 3, the switching valve 18 is controlled as follows.

That is, the throttle opening signal shows a voltage change as shown in FIG. 5 according to the throttle opening of the engine 1.
A throttle opening detector 19 that generates a signal E ₁ , a vehicle speed detector 20 that generates a vehicle speed signal E ₂ that shows a voltage change as shown in FIG. A gear position detector 21 is provided which generates a gear position signal _E3 indicating a stepwise voltage change as shown in FIG.
E ₁ and _the speed change signal E ₃ are added in the arithmetic circuit ₂₂ to generate a composite signal E ₄ as shown in FIG. A logic signal of "0" or "1" is generated by determining whether the voltage is higher than the voltage of _the composite signal _E4 . ” logic signal is generated,
When a logic signal of "0" is input to the electromagnetic circuit 18a of the switching valve 18, the switching valve 18 is switched to the refueling position and the hydraulic clutch 12 is connected. given characteristic line X ₂ ,
According to X ₃ and X ₄ , the high-speed transmission system is
GH was established.

In the illustrated example, the comparison circuit 23 is configured to have hysteresis characteristics, and the downshift from the high-speed transmission system GH to the low-speed transmission system GL is performed at a slightly lower speed than the above characteristic lines X ₂ , X ₃ , and X ₄ . The test is performed in the low-speed region according to the offset characteristic lines X ₂ ′, X ₃ ′, and X ₄ ′.

According to the present invention, the control according to the characteristic line of FIG. It is equipped with a low-speed transmission system holding device 24 that holds the gear position of the transmission 4 in the low-speed transmission system GL.To explain this in detail, the holding device 24 in the one shown in the figure is used to connect and disconnect the transmission clutch 2. A clutch detector 25 for detecting and the comparison circuit 23
and the electromagnetic circuit 18a.
As shown in FIG. 3, the detector 25 includes a timer circuit 27 and a clutch switch 28 on its input side.
When the input voltage is turned on and off, the input voltage to the timer circuit 27 is switched between a low level and a high level, respectively, and when the input voltage is switched to a low level, the timer circuit 27 immediately receives a logic signal of "1". , and continues to output a logic signal of "1" until a predetermined time has elapsed even after switching from low level to high level, and then outputs a logic signal of "0" after the elapse of a predetermined time. and apply this logical symbol.
It was made to be input to OR gate 26.

Here, the clutch switch 28 is, for example, a fourth
As shown in the figure, the movable contact 28a contacts the fixed contact 28b and is turned on when the shift clutch 2 is released by pressing the clutch pedal 29 in the vehicle interior.

When the shift clutch 2 is released, the input voltage of the timer circuit 27 becomes low level by turning on the switch 28, and a logic signal of "1" is output from the timer circuit 27, which is output from the OR gate. 26 and generated from the comparator circuit 23, the electromagnetic circuit 18
Even if a logic signal of "1" is input from the OR gate 26 to a, and the switch 28 is turned off by connecting the gearshift clutch 2 and the input voltage of the timer circuit 27 is switched to a high level, this switching will not occur. Until a predetermined period of time has elapsed, the timer circuit 2
7 outputs a logic signal of "1", and similarly a logic signal of "1" is input to the electromagnetic circuit 18a,
Thus, while the shift clutch 2 is released and until a predetermined period of time has elapsed after the clutch 2 is connected, the switching valve 18 is kept in the oil draining position and the gear stage of the sub-transmission 4 is changed. is held in the low-speed transmission system GL.

Next, to explain the operation in actual driving, for example, select the 1st gear of the main transmission 3, accelerate, and then move to the 9th gear.
Considering the case where the main transmission 3 is shifted up from 1st gear to 2nd gear at the vehicle speed indicated by A in the figure, the gear change is performed with the shift clutch 2 released first, and at this point, the gear change is normally performed. The accelerator pedal is completely off, and even when the gear shift clutch 2 is subsequently connected, the accelerator pedal has not yet been depressed much and the throttle opening is close to zero.

Therefore, the low speed transmission system holding device 24 as in the present invention
As can be seen from the characteristic _line When the value is increased to the value indicated by B in a short period of time, the sub-transmission 4 switches to the high-speed transmission system.
The gear shift is downshifted from the GH to the low speed transmission system GL, causing a gear change shock due to the downshift after the shift of the main transmission 3, and a delay in acceleration due to the delay in the downshift. However, according to the present invention, while the shift clutch 2 is released and until a predetermined period of time has elapsed after the clutch 2 is connected, the low speed transmission system holding device 24 is operated to shift the sub-transmission 4. The stage is a low-speed transmission system GL regardless of the driving condition.
If the throttle opening is increased beyond the value shown by C in FIG. 9 within the predetermined time, the low-speed transmission system GL will continue to maintain the throttle opening according to the characteristic line _X2 in FIG. No downshift as described above occurs.

Incidentally, the gear stage of the sub-transmission 4 is previously switched to and held in the low-speed transmission system GL when the shift clutch 2 is released, and no shock occurs due to this switching.

Thus, according to the present invention, while the transmission clutch is released by the low-speed transmission holding device,
The gear position of the auxiliary transmission is maintained in the low-speed transmission system for a predetermined period of time after the clutch is connected, and the auxiliary transmission is downshifted when the accelerator pedal is depressed immediately after the main transmission is shifted. Moreover, the switching to the low-speed transmission system by the device is performed with the gear shifting clutch in the released state, and the occurrence of shock due to this switching is also prevented, and the above-mentioned disadvantages of the conventional system are reliably eliminated. It has a possible effect.

[Brief explanation of drawings]

Fig. 1 is a diagram showing an example of a vehicle transmission to which the present invention is applied, Fig. 2 is a diagram showing an automatic switching control circuit of the sub-transmission, and Fig. 3 is a diagram showing a control circuit for automatic switching of the sub-transmission. A circuit diagram of a clutch detector, FIG. 4 is a cutaway view of a clutch switch provided in this detector, and FIG.
Figures 7 to 7 are signal characteristic diagrams of the throttle opening degree detector, vehicle speed detector, and gear position detector provided in the control circuit, and Figure 8 is a characteristic diagram of the composite signal output from the arithmetic circuit provided in the control circuit. , FIG. 9 is a diagram showing the switching characteristics of the sub-transmission. 1...Engine, 3...Main transmission, 4...Sub-transmission, GH...High speed transmission system, GL...Low speed transmission system,
12...Hydraulic clutch, 24...Low speed transmission system holding device.

Claims (1)

[Claims] 1 A manual main transmission connected to the engine via a transmission clutch, with two high and low gears in series.
A vehicular transmission comprising a sub-transmission connected to a sub-transmission having a gear transmission system, wherein the sub-transmission is automatically switched according to the throttle opening of the engine and the vehicle speed. A low-speed transmission system holding device is provided that holds the gear position of the auxiliary transmission in the low-speed transmission system while the transmission clutch is released and until a predetermined period of time has elapsed after the transmission clutch is connected. Characteristic control device for vehicle transmission.