JPH0130027B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a shift control device for an auxiliary transmission that prevents the occurrence of shift failures when the lubricating oil temperature of the auxiliary transmission decreases.

[Background technology]

Some vehicles are equipped with an auxiliary transmission in order to reduce fuel consumption and engine noise.

This sub-transmission is installed on the input side or output side of the main transmission included in the transmission unit, and has two stages: high speed side (economy side E) and low speed side (power side P). This is for switching.

To control the switching of the auxiliary transmission, first, a changeover switch provided on the driver's seat is operated, and a speed change command is supplied to a speed change control signal generation section comprised of a microcomputer or the like. The shift control signal generating section also receives a detection signal of clutch pedal operation, and is energized by this detection signal to send a shift control signal to the switching drive device of the auxiliary transmission in accordance with the shift command to operate the actuator in a predetermined direction. I'm starting to do that.

By operating this actuator, the gear of the sub-transmission is switched from the economy side to the power side, or from the power side to the economy side.

By the way, when the outside temperature is low and the temperature of the lubricating oil in the sub-transmission is low, such as in winter, the viscosity of the lubricating oil is high, so the shift time will inevitably become longer. Therefore, during normal clutch operation time, the clutch will engage prematurely in the neutral state where gear shifting has not yet been completed, putting a strain on the synchromesh mechanism and potentially causing damage.

Furthermore, if the neutral state continues for a long time when descending a slope, the rotational speed between the gears to be connected increases, causing loss of synchronization and causing the vehicle to run in neutral without engine braking, which is dangerous.

[Purpose of the invention]

In consideration of the above-mentioned facts, the present invention has been devised to prevent the gear shifting operation when the lubricating oil temperature of the sub-transmission is low, thereby eliminating the reduction in strength of the synchronized mesh mechanism, etc., and preventing the danger of neutral running. The purpose is to obtain a speed change control device for the aircraft.

[Structure of the invention]

A shift control device for a sub-transmission according to the present invention includes a shift command generator that generates a shift command, a temperature detector that detects information regarding the lubricating oil temperature of the sub-transmission,
a shift control signal generator that generates a shift control signal in accordance with a shift command; a prohibition circuit that prohibits the output of the shift control signal when the lubricating oil temperature detected by the temperature sensor is below a predetermined value; The present invention is characterized in that it includes a speed change drive device that performs speed change drive of the sub-transmission.

Therefore, since the lubricating oil temperature is high when the shift control signal is generated, the time required for shifting is short, and the shifting operation can be reliably completed within the normal clutch operation time.

On the other hand, if the lubricating oil temperature is low, gear shifting is prohibited even if the driver issues a gear shifting command, so the clutch will not engage prematurely during gear shifting, thereby avoiding a decrease in the strength of the synchronized mesh mechanism, etc. At the same time, the neutral state does not last long, which increases safety by preventing the occurrence of dangers such as neutral driving due to inability to synchronize when going downhill.

[Embodiments of the invention]

Embodiments of the apparatus according to the present invention will be described below based on the drawings.

FIG. 1 shows a first embodiment of the device according to the invention, in which depression of a clutch pedal 10 is detected by a clutch switch 12, which is a momentary switch.

Also, a mode changeover switch 1 that generates a gear shift command.
4 is a momentary switch that is turned off when the vehicle is left unused and turned on when it is operated, and generates a gear change command when the switch is turned on.

Further, the vehicle weight is detected by a vehicle weight detector 11 consisting of a load sensor. This vehicle weight detector 11 is provided at a predetermined location on the vehicle body, and is turned on when the vehicle weight W is greater than a predetermined reference weight Wc, and turned off when it is less than or equal to the reference weight.

This vehicle weight detection signal is used to determine whether to shift the gear of the auxiliary transmission 13 to the power side or the economy side during the initial setting operation, as will be described later.

Furthermore, in this embodiment, the lubricating oil temperature of the sub-transmission 13 is detected by an oil temperature detector 15. This oil temperature detector 15 consists of a temperature sensor and outputs the detected temperature as a digital signal.

This oil temperature detection signal indicates that the temperature of the lubricating oil is at a predetermined reference temperature, except when the gear is changed during the initial setting operation.
This is to allow the sub-transmission 13 to perform a gear change operation only when the temperature is higher than Kc, and to prohibit the gear change operation even if the driver issues a gear change command when the temperature is below the reference temperature and the viscosity of the lubricating oil is high.

As a result, it is possible to stop the start of a shift operation which takes a long shift time, and to prevent the clutch from engaging prematurely during a shift, damaging the synchromesh mechanism or causing neutral running.

Note that the lubricating oil temperature of the sub-transmission 13 is detected not only by directly detecting the oil temperature as described above, but also indirectly by determining the outside air temperature using an air temperature sensor and performing a predetermined conversion. You can do it like this.

The detection signal of the clutch switch 12, the command of the mode changeover switch 14, and the vehicle weight detector 11
The detection signal of the oil temperature detector 15 is supplied to the shift control signal generator 16, and the shift control signal generator 1
The speed change control signal obtained from 6 is transmitted to actuator 1.
8.

The shift control signal generator 16 is connected to the changeover switch 14
When a shift command is supplied by the operation, the gearshift preparation is set internally, and if a clutch operation detection signal is supplied within a predetermined time after the shift command is generated, a shift control signal is generated in accordance with the shift command. If the clutch is not operated and the detection signal is not supplied within a predetermined time, the preparation setting based on the shift command is canceled.

Therefore, even if you are distracted by other driving operations and do not press the clutch pedal 10 as part of a series of switching operations after operating the changeover switch 14, the shift command from the changeover switch 14 will still be issued. Since the clutch is released and returns to the state before the changeover switch 14 was operated, even if the clutch is subsequently operated to change the main transmission, the auxiliary transmission 13 will not be changed inadvertently, and the changeover switch 1
If 4 is operated, it is accepted as a new regular gear shift command, so there is no risk of erroneous operation, and operability and safety for the driver are improved.

The actuator 18 is included in a speed change operation device that performs a speed change operation, and when the lever 20 is driven by a speed change control signal, the speed change sleeve 2 is moved.
2 is operated.

The shift sleeve 22 is operated by the actuator 18 to change the shift of the sub-transmission 13. As mentioned above, this sub-transmission 13 is provided on the input side or the output side of the main transmission included in the transmission unit 24 connected to the engine 17, and is connected to the economy side E and the power side P. Two stages of switching are performed.

Actuator 18 may be configured as shown in FIG. The actuator 18 is provided with an air actuator 28, and a drive shaft 32 connected to a diaphragm 30 of the air actuator 28 operates the lever 20 (see FIG. 1).

First electrodes formed on both sides of the diaphragm 30
The air chamber 34 and the second air chamber 36 are equipped with solenoid valves 38 and 40.
These solenoid valves 38, 4 are connected to the pressure regulating ports of
The low pressure port 0 is connected to the vacuum tank 4 as a negative pressure source via a surge tank 42 and a check valve 44.
Connected to 6. In addition, each high pressure port has a filter 48,
50 to the atmosphere.

Negative pressure in the vacuum tank 46 is created by a vacuum pump 19 (see FIG. 1) driven by the rotation of the engine 17.

Furthermore, the solenoid 5 of the electromagnetic valve 38, 40
The energization control of 2 and 54 is performed by a control signal output from the speed change control signal generator 16.

The first air chamber 34 is opened by energizing the solenoid 52.
When the solenoid 54 is energized, the second air chamber 52 is energized and the solenoid 5 is energized to the power side P.
4, the sub-transmission is operated to shift to the economy side E.

One of the solenoids 52 and 54 is always energized, and even after the gear change is completed, the diaphragm 30 is urged toward the P side or the E side to prevent the gear from slipping out.

The vacuum tank 46 mentioned above has brakes,
It is also used as a negative pressure source for operating clutches, etc. When the brake, clutch, etc. are used frequently, the negative pressure decreases and the speed change drive of the sub-transmission 13 becomes incomplete. Similarly, when the rotation speed of the engine 17 decreases, the vacuum generating force of the vacuum pump 19 decreases, and as negative pressure is used, the negative pressure in the vacuum tank 46 decreases.

For this reason, a negative pressure detection switch 21 is provided at the outlet of the vacuum tank 46 on the side of the accumulator 18 to detect the magnitude of the negative pressure. This negative pressure detection switch 21 is turned on when the negative pressure of the vacuum tank 46 is larger than a predetermined upper reference pressure Pc when increasing.
It has a hysteresis characteristic as shown in FIG. 9, which turns off when the lower reference pressure P'c is lower than the decreasing pressure.

Further, the engine 17 is provided with an engine rotation speed detector 23 that detects the engine rotation speed.
As shown in FIG. 9, this engine rotation speed detector 23 is connected to an engine rotation speed sensor 25 that outputs a signal with a frequency corresponding to the rotation speed of the engine 17, and to the output side of this engine rotation speed sensor 25. The F/V converter 26 generates a voltage signal proportional to the signal, the reference voltage source 29 generates a reference voltage Vc corresponding to a predetermined engine speed, and the outputs of the F/V converter 26 and the reference voltage source 29 are compared. It consists of a comparator 31 that is turned off when the output of the F/V converter 26 is large and turned on when it is small.

This engine rotation speed detector 23 is connected to the engine 1
7 is stopped or vacuum pump 19
It is designed to detect when the engine rotational speed is not high enough to generate sufficient negative pressure for variable speed drive, etc.

The detection signals of the negative pressure detection switch 21 or the engine rotation speed detector 23 permit the gear shifting operation only when the negative pressure for shifting drive of the auxiliary transmission 13 can be maintained larger than a predetermined value, This is to prohibit the gear shift operation even if the driver gives a gear shift command if the gear shift is below or there is a risk of the gear shift being lower than that.

This prevents incomplete gear shifting due to insufficient negative pressure, prevents the gear from stopping in neutral, which poses a danger to driving, and prevents damage to the synchronized mesh mechanism due to misshifts. can.

Note that the engine rotation speed detector 23 may be configured using a tachometer.

64 is a buzzer, 66 is its drive control circuit, 70 and 72 are indicator lamps, and 68 is its drive control circuit.

The buzzer 64 and indicator lamps 70 and 72 indicate the economy side or power side mode status of the auxiliary transmission 13, or the fact that the gear shift is in progress. A warning prohibiting shifting will be issued.

In the device according to the present invention, as shown in FIG. 1, a detection means 26 for detecting the gear change direction of the auxiliary transmission, that is, the current position of the gear, is provided in association with the shift sleeve 22 in this example, This detection means 2
The detection output of 6 is supplied to the speed change control signal generator 16.

As an example of the detection means 26 is shown in FIG. 3, the detection means 26 is attached to a cam 56 provided in relation to the speed change sleeve 22, and at a position where it contacts a top portion 58 of the cam 56, with a predetermined distance maintained therebetween. Consists of a pair of switches SW _P and switch SW _E , and the power P
When the switch SW P is in the neutral position just before the end of switching to the economy E side, the switch SW _P is turned on, and conversely, when the switch is in the neutral position just before the end of switching to the economy E side, the other switch SW _E is turned on. ing. Signals from these pair of switches SW _P and SW _E are used as detection outputs of the detection means 26 .

During the switching operation, these switches SW _P and SW _E detect that the auxiliary transmission is about to end the gear switching operation, and turn on the buzzer 64 and indicator lamp 7.
This is for controlling 0,72.

Also, immediately after turning on the ignition switch (JGS/W), turn on one switch SW _P or SW _E to check whether the gear position before starting operation is power side or economy side. It also has a function of initializing the speed change setting mode of the speed change control signal generator 16 (switched in response to a speed change command) to match the current position of the gear.

As a result, the clutch pedal 10 is
Even if you operate the auxiliary transmission, there will be no unintentional shifting of gears in the auxiliary transmission, and you can enjoy ease of use by being able to start driving in the same mode as the last time you drove without having to perform any extra switching operations. .

Note that when the engine is started, if the gear is in the neutral state for some reason, or if the switches SW _P and SW _E are malfunctioning and are both on or off, the shift control signal generator 16
An initial setting operation is performed, and a shift control signal is generated to energize the solenoid 54 or 52 depending on the weight of the vehicle to switch the gear to the power side or the economy side.

This eliminates the inability to start at the start of driving, and also enables reliable gear shifting by accurately grasping the gear position.In addition, when the vehicle weight is large, the power is applied to the power side to reduce the burden on the clutch when starting. This is done to prevent damage by reducing the weight of the vehicle, and to improve fuel efficiency by shifting the gear to the economy side if the vehicle weight is small.

As described above, when the switches SW _P and SW _E are out of order, the buzzer 64 and indicator lamps 70 and 72 are controlled during the switching operation in relation to the passage of time from the switching start point.

FIG. 4 shows an example of a speed change control device including a speed change control signal generator 16.
has a microcomputer 16A, a vehicle weight detector 11, a changeover switch 14, a clutch switch 12, and a pair of detection switches SW _P and SW _E are connected to each other via inverters 62, 62A to 62D, respectively, and an oil temperature detector 15 is directly connected to , the engine rotation speed detector 23
Further, through the OR circuit 63, the negative pressure detection switch 2
1 is connected to the input port of the microcomputer 16A via the inverter 62E and the OR circuit 63, and each detection signal and detection data (in the case of the oil temperature detector 15) are supplied to the microcomputer 16A. Here, the output of the OR circuit 63 is a negative pressure abnormality detection signal.

On the other hand, solenoids 52, 54, a buzzer drive control circuit 66, and a lamp drive control circuit 68 are connected to the output port of the microcomputer 16A, and necessary control signals are sent to each of them.

The microcomputer 16A has an interrupt processing function.
A hard timer (not shown) is connected that is started under the control of A and generates an interrupt when it times out.

The microcomputer 16A has a function of controlling the overall speed change of the auxiliary transmission according to a predetermined procedure based on a program stored in the memory, and performs flag processing to check various conditions.

The microcomputer 16A performs a predetermined initial setting operation when starting the engine, and then prepares a mode for the switching direction when a shift command is supplied by operating the changeover switch 14, and operates the clutch pedal within a predetermined time after the shift command is issued. When the depressing operation No. 10 is performed, this detection signal sends a control signal to the solenoid 52 or 54 on the setting mode side and starts energizing it.

When this solenoid 52 or 54 starts to be energized, the gears are switched and driven. Once one solenoid 52 or 54 is energized in this manner, the gear shift control signal output continues until the clutch pedal 10 is operated in the next switching operation, and the energized state is maintained during this time.

Therefore, during a shifting operation, even if the clutch pedal 10 is released while the auxiliary transmission is still in neutral, the solenoid 52 or 54 will continue to be energized, thereby ensuring that the auxiliary transmission gear is completely and reliably in the economy or power position. switched to the side. Furthermore, since the excitation continues even after the gear change is completed, there is no chance of gear slippage during driving.

However, when the lubricating oil temperature is below a predetermined reference value, when the negative pressure in the negative pressure path is below a predetermined reference value, and when the rotation speed of the engine 17 is below a predetermined reference value, At this time, the variable speed drive is stopped to avoid neutral running and to prevent damage to the synchronized mesh mechanism.

Note that the microcomputer 16A further generates a buzzer control signal and supplies it to the drive control circuit 66 for the buzzer 64, so that the buzzer 64 is driven from the time when excitation switching of the solenoid 52 or 54 is started until the switching operation is completed. Ru. The buzzer 64 is used to notify the driver that the sub-transmission is in the process of shifting.

Additionally, if the lubricating oil temperature is low or high or the negative pressure is abnormal, a continuous buzzer sounds to warn you.

Further, the microcomputer 16A is configured to turn on and off a power side indicator lamp 70 or an economy side indicator lamp 72 via a lamp drive circuit 68. After the switching operation starts, the corresponding lamp blinks until the switching operation is completed, and then only the display lamp corresponding to the current mode lights up until the next switching operation starts, and the mode to the power side or economy side is switched on. This is to notify the driver of the current mode being switched and of the current mode being switched.

A normal switching operation of the shift control device configured as described above will be outlined with reference to FIG. 5. The figure is a time chart of the switching operation from the economy side to the power side. When the mode changeover switch (using a momentary switch) 14 is operated at time _t1 ,
The command pulse (mode switching pulse) shown in Figure A is generated, and the power side mode is prepared. As a result, the power side switching display lamp 72 blinks for a certain period T (FIG. 3B).

When the clutch pedal 10 is depressed at any time _t2 within a predetermined time _T1 after the command pulse is generated,
A detection signal (clutch pulse) (D in the same figure) is obtained from the clutch switch 12, and at the rising timing of the detection signal (clutch pulse), a shift control signal is output to the solenoid 52 and energization is performed (E in the same figure), so that the gear changes as shown in the figure. As shown in G, the power is switched from the economy E side to the power P side through the neutral position N. The economy side solenoid 54 stops outputting the speed change control signal and is de-energized at the rising timing of the detection signal of the clutch switch 12. Also, at this time, the economy side indicator lamp 70 is turned off.

Since the cam 56 shown in FIG. 3 moves in conjunction with this switching operation, the power side detection switch is activated by the cam 56 just as it passes through the neutral position N.
When the SW _P is turned on (I in the same figure) and a predetermined time τ has elapsed from the ON time t ₃ to a time t ₄ , the power side switching indicator lamp 72 is turned on.

The buzzer is emitted for a period of time t ₂ to _{t 4} as shown in Drawing J.

The switching operation to the economy side is also the same as described above, so a description thereof will be omitted.

Next, the above control operation will be explained in detail according to the flowcharts shown in FIGS. 6 and 7. FIGS. 7A to 7E show interrupt processing. For example, (step 100)
is abbreviated as 100. Also, in the flowchart,
Set the power side, economy side, treble, bass, solenoid, ignition, and switch to P.
They are abbreviated as E, H, L, SOL, IG, and S/W.

As shown in FIG. 6, the initial operation is performed after waiting for the ignition switch to be turned on (step 100). That is, in step 102, the RAM work area is initialized and each flag C, D,
After setting F, G and T ₁ , T ₂ , T ₃ to 0, check the detection switches SW _E and SW _P (step 104,
106, 108), when the gear is in the economy side and only the detection switch SW _E is on, F related to the gear position is set to F=0 and the economy side solenoid 54
When electricity is turned on, the economy side indicator lamp 70 is turned on.
(Step 110).

Conversely, when the gear is on the power side and only the detection switch SW _P is on, F=1 and the power side solenoid 52 is energized and the power side indicator lamp 72 is turned on 112.

Through the above operations, the current mode of the gear before the start of operation matches the set mode.

When the detection switches SW _E and SW _P are both on or off (including when the gear is in neutral), if the vehicle weight W is greater than the reference weight Wc, flags C, D, F, and M are set to 1 and the next flow is executed. The power side solenoid 52 is energized to switch the gear to the power side, and the power side indicator lamp 72 flashes to indicate to the driver that the gear is scheduled to be switched to the power side (steps 114 and 116).

Conversely, if the vehicle weight W is less than the reference weight Wc, flags C, D, M = 1, F = 0 are set, and the economy side solenoid 54 is energized in the next flow to switch the gear to the economy side. The indicator lamp 70 flashes to indicate to the driver that the switch to the economy mode is scheduled (step
114, 118).

Here, the reference weight Wc is a value that determines which one to switch to, and is experimentally set in advance in consideration of the degree of damage to the clutch at the time of starting and the fuel consumption.

With this process, even if the gear is in neutral when starting the engine, the gear is shifted to the power side or economy side depending on the weight of the vehicle, making it possible to start without requiring the driver to change gears. Since it is applied to the power side, there is no risk of damaging the clutch when starting, while if the weight is small, it is applied to the economy side, which can reduce fuel consumption.

Furthermore, even if the detection switch SW _P or SW _E is out of order, the current gear position can be accurately grasped, allowing reliable gear shifting operations.

Next, when the engine starts, the detection switch SW _E ,
When SW _P is neither on nor off, initially G=0 due to the initialization, so steps 120 and 122 are repeated until M=1. Here, the flag M is set to 1 when an interrupt occurs at the rising edge when the mode changeover switch 14 is turned on (FIG. 7C (step 208)).

The negative pressure is then checked for normality (step
124). When normal, the process proceeds to step 126 and then to step 128, but if the negative pressure in the negative pressure path is lower than the reference negative pressure Pc, or if the engine 17 is stopped or the rotational speed is low and the negative pressure supply is low, the negative pressure is If the pressure is abnormal, the buzzer 64 will sound intermittently at a low tone to warn the driver, clear M, and proceed to step
Return to 120 (steps 124, 130).

As a result, the shift command is canceled, and it is possible to prevent an incomplete shift operation from occurring due to a drop in negative pressure.

After the negative pressure returns to normal, press the mode selector switch 1.
4 is turned on, the negative pressure abnormality warning is canceled in steps 126 and 134.

Next, since D=0 initially, the oil temperature K is read (step 136), and it is checked whether the oil temperature K is greater than the reference oil temperature Kc (step 138). If the oil temperature is higher than Kc, the process advances to step 142 via step 140, but if the lubricating oil temperature of the sub-transmission 13 is lower than Kc, the buzzer 64 is sounded intermittently at a high pitch to indicate that the oil temperature is abnormal, and the operation is started. M
Clear and return to step 120 (step 138,
144).

As a result, the shift command is released, and it is possible to prevent damage to the synchromesh mechanism and the like due to early engagement of the clutch and the danger of neutral running due to the long shift time due to a drop in oil temperature.

When the negative pressure is normal and the mode changeover switch 14 is turned on after the oil temperature becomes higher than Kc, the oil temperature abnormality warning is canceled in steps 148 and 150.

When both negative pressure and oil temperature are normal, the step
Since T ₁ = 0 due to initialization of 102,
When the mode selector switch 14 is turned on, the timer
_T1 starts (steps 152, 154). Next, a flag _T1 indicating that timer _T1 is being activated is set (step 156). At this time, the timer
_T1 Flag G is set to 1 to perform processing when the clutch is not operated during startup (step
158).

Next, in order to invert and memorize the current mode state before switching, flag F is checked and F.0 is set to 160.
In this case, the flag F=1 is set and the P display lamp 72 is blinked (steps 162 and 164), and F=1.
In this case, the flag F is set to 0 and the E indicator lamp 70 is blinked (steps 166 and 168).

That is, when the mode changeover switch 14 is turned on, after a predetermined check is performed, the lamp 70 or 72 starts blinking.

As shown in FIG. 7D, the flag C is set after M is set, that is, after the mode changeover switch 14 is turned on, an interrupt is set at the rising edge when the clutch switch 12 is turned on. 210, 212). Therefore, even if the mode changeover switch is turned on, unless the clutch switch is turned on, C=0 remains, and the process returns to step 120 (step 170). In this case, if timer _T4 times up without any clutch operation, an interrupt flag is flagged as shown in Figure 7A.
_T1 and M are reset. Then, since G=1 (step 158), the flag F is returned to the current mode state by the processing of steps 300 to 310, and the blinking of the display lamp 70 or 72 is stopped and the original state is restored. Then, G=0. That is, even if the mode changeover switch 14 is turned on, if the clutch switch 12 is not turned on within a certain period of time, the turning on of the mode changeover switch 14 will be ignored.

If the clutch switch 12 is turned on before the timer _T1 times up, the process proceeds from steps 152 to 170, and then, when both the solenoids 52 and 54 are normal, F=1, that is, switching from the economy side to the power side. If so, the power side solenoid 52 is turned on, the economy side solenoid 54 and the E indicator lamp 70 are turned off, and the buzzer 64 is sounded at a high pitch (steps 172 and 174).

Contrary to the above, if F=0, the economy side solenoid 52 is turned on, the power side solenoid 54 and the P display lamp 72 are turned off, and the buzzer 64 sounds at a low tone (steps 172 and 176).

However, when starting the engine, the detection switch
When SW _E and SW _P are both on or off, C, D,
Since F=1 or C, D=1, and F=0, the process goes from step 128 to step 172 to step 174 or 176, where an initial setting operation is performed.

In the process of step 174 or 176, the solenoid 54
Alternatively, the switching operation is performed by turning on 52. Subsequently, timer _T2 is started (steps 178, 180) and flag _T2 is set (steps 182, 184). Here, flag _T2 indicates that timer _T2 is being activated. This timer _T2 is used to allow sufficient time to complete the switching operation when the detection switch SW _P or SW _E is out of order, and then switch the indicator lamps 70, 72 and the buzzer 64. .

After setting the T ₂ flag, solenoid 52
Or the mode switching operation progresses by turning on 54,
If the power detection switch SW _P is turned on while switching to the power side, or if the economy detection switch SW _E is turned on while switching to the economy side, step 186 or 188 is executed.
From 190 to 192, it moves to 194. Timer _T3 is started (step 194) and flag _T3 is set (step 196). Here, flag _T3 indicates that timer _T3 is being activated.

When the timer _T3 (set time .tau., for example 0.2 seconds) times up, an interrupt is generated and the flag _T3 is reset as shown in FIG. 7E (step 214).
Then, the process moves from step 198 to step 400, and the power side display lamp 72, which was blinking when switching to the power side, is turned on and the buzzer 64 is turned off (step 402). When switching to the economy side, the economy side solenoid 54 is turned off, the economy side indicator lamp 70, which was blinking, is turned on, and
The buzzer 64 is turned off (step 404). Flags C, G, M are then reset (step
406), the process returns to step 120 and the above-mentioned processes for the next mode switching operation are performed.

In addition, in step 186 or 188 described above, solenoid 5
_The detection switch _SW
Or, if SW _E does not turn on, or the detection switch
SW _P or SW _E is turned on, but the other detection switch is
If SW _E or SW _P is also on (step 190,
192), an interrupt occurs when the timer _T2 times up, and the program waits for the flag _T2 to be reset as shown in FIG.

Thereby, even if the detection switch fails, gear switching can be performed reliably.

In this embodiment, the mode changeover switch 14 and the clutch switch 12 are momentary switches, which are extremely easy to operate.

In addition, as shown in FIG. 10, a temperature sensing element 90 for oil temperature detection (having the temperature-resistance characteristics shown in FIG. 11) is used.
After comparing the detection signal change as shown in Fig. 12 caused by the resistance change with respect to the oil temperature with the reference signal (corresponding to the oil temperature Kc) using the comparator 92, the transistor
By connecting Tr1 in series with transistor Tr2, which turns on and off Tr1 and turns it on and off by operating the changeover switch 14A, and switching transistor Tr3, a circuit for inhibiting gear shift command output when the oil temperature drops is constructed in hardware. You can do it like this.

〔Effect of the invention〕

As explained above, in the shift control device for the auxiliary transmission according to the present invention, information regarding the lubricating oil temperature of the auxiliary transmission is detected by the oil temperature detector or the outside temperature detector. When the lubricating oil temperature based on this detection signal is equal to or higher than a predetermined value, the shift control signal generation circuit generates a shift control signal in accordance with the shift command and drives the sub-transmission to shift.

Therefore, since the lubricating oil temperature is high when the shift control signal is generated, the time required for shifting is short, and the shifting operation can be reliably completed within the normal clutch operation time.

On the other hand, if the lubricating oil temperature is low, gear shifting is prohibited even if the driver issues a gear shifting command, so the clutch will not engage prematurely during gear shifting, thereby avoiding a decrease in the strength of the synchronized mesh mechanism, etc. In addition, the neutral state does not continue for a long time, and it has the excellent effect of increasing safety by preventing the occurrence of dangers such as neutral driving due to inability to synchronize when going downhill.

[Brief explanation of drawings]

Fig. 1 is a system diagram of the main parts of the device of the present invention, Fig. 2 is a configuration diagram of the actuator, Fig. 3 is an explanatory diagram of the gear change direction detection means, and Fig. 4 shows an example of the main parts of the gear change control device. A system diagram, FIG. 5 is a time chart for explaining the operation, and FIGS. 6A, 6B, and 7 are flow charts for explaining the operation.
FIG. 8 is an explanatory diagram showing the operating characteristics of the negative pressure detection switch, FIG. 9 is a block diagram showing the engine rotation speed detector, and FIG. 10 is a circuit configuration diagram showing another embodiment.
11 and 12 are explanatory diagrams of the operation of FIG. 10. 11... Vehicle weight detector, 12... Clutch switch, 14... Mode changeover switch, 15...
Oil temperature detector, 16... Speed change control signal generator, 18
... Actuator, 21 ... Negative pressure detection switch, 22 ... Speed change sleeve, 23 ... Engine rotation speed detector, 26 ... Switching direction detection means, 52,
54...Solenoid.

Claims (1)

[Claims] 1 A shift command generator that generates a shift command, a temperature detector that detects information regarding the lubricating oil temperature of the sub-transmission, a shift control signal generator that generates a shift control signal according to the shift command, and a temperature detector that detects The present invention is characterized by comprising: a prohibition circuit that prohibits the output of the shift control signal when the lubricating oil temperature is below a predetermined value; and a shift drive device that drives the sub-transmission to shift based on the shift control signal. Shift control device for sub-transmission.