JPH0676760U - Transmission control device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a transmission control device capable of preventing gears from being inadvertently switched even if a signal conversion unit malfunctions. [Structure] The CPU 103 decodes an input signal V _i corresponding to the position of the change lever into a predetermined control signal V _o and outputs the control signal V _o . The gate signal generator 116 outputs a low level signal and a high level signal, respectively, according to the position of the switch 101 that is switched when the gear is switched and when the gear is not switched. A gate circuit 108 passes a control signal V _o in response to the low level signal, to shield the control signal V _o in response to the high level signal. Transmission control unit 115 in response to control switching of the gear to the control signal V _o.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a transmission control device that controls gear switching of transmissions such as buses and trucks.

[0002]

[Prior art]

Conventionally, various transmission control devices have been used to electrically control gear switching operations of transmissions such as buses and trucks (see, for example, Japanese Utility Model Laid-Open No. 3-96922). FIG. 3 is a circuit diagram of a transmission control device that has been conventionally used. In FIG. 3, when a clutch (not shown) is brought into a contact state by operating a clutch plate (not shown), a switch 301 is opened, and a control terminal of a central processing unit (CPU) 303 serving as a signal converter is provided. A high level signal is input via the resistor 302. In response to the high level signal, the CPU 303 decodes the input signal V _i corresponding to the position of the change lever (not shown) and outputs the control signal V _o from each output terminal. The transistors 305 ₁ to 305 _n forming the transmission control unit 307 receive the control signal V _o via the corresponding resistors 304 _{1 to} 304 _n, and are turned on or off depending on the signal level of the control signal V _o. Becomes As a result, the magnet valves 306 _{1 to} 306 _n for transmission control connected to the transistors 306 _{1 to} 306 _n in the ON state are driven and set to the gear corresponding to the position of the change lever.

[0003]

[Problems to be solved by the device]

Since the conventional transmission control device is configured as described above, when the CPU 303 as the signal conversion unit performs an abnormal operation such as a runaway or a malfunction, an abnormal control signal V _o unrelated to the position of the change lever is generated. Is output. Thus, different transistors 305 ₁ to 305 _n are driven and the transistor ₃₀₅ 1 to 305 _n to be driven originally. Therefore, there was a problem that the gear suddenly switched from the neutral position to the second speed position and the vehicle suddenly started, even though the change lever was not operated.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a transmission control device that can prevent gears from being inadvertently switched even when the signal conversion unit malfunctions.

[0005]

[Means for Solving the Problems]

 The transmission control device of the present invention includes a signal conversion unit that converts an input signal corresponding to the position of the change lever into a predetermined control signal and outputs the signal, a first state when the gear is switched, and a second state when the gear is not switched. A switch that is switched to a state, a gate signal generator that outputs a first signal and a second signal when the switch is in the first state and the second state, respectively, and a switch that responds to the first signal. A gate unit for transmitting and outputting the control signal and blocking the control signal in response to the second signal, and a transistor for switching control of a transmission gear based on the control signal output from the gate unit. And a mission control unit.

[0006]

[Action]

 The signal converter converts an input signal corresponding to the position of the change lever into a predetermined control signal and outputs it. The gate signal generator outputs the first signal when the gear switching operation is performed, and outputs the second signal when the gear switching operation is not performed. The gate unit outputs the control signal in response to the first signal and shields the control signal in response to the second signal. The transmission control unit controls gear switching in response to the control signal from the gate unit.

[0007]

【Example】

FIG. 1 is a circuit diagram showing an embodiment of the present invention. In FIG. 1, one terminal of a switch 101 that opens and closes in response to an operation of a clutch plate (not shown) is grounded, and the other terminal is connected to a power supply _Vcc via a resistor 102. An input signal V _i corresponding to the position of a change lever (not shown) is input to the input unit of the CPU 103 as a signal conversion unit, and a control signal V _o obtained by decoding the input signal V _i is output. There is. The latch signal of the CPU 103 is supplied to the control terminal of the latch circuit 107. Control signal _{V o} through the latch circuit 107 is input to the gate circuit 108 as a gate portion. The output terminal of the gate circuit 108 is connected to the corresponding base terminals of the driving transistors 105 _{1 to} 105 _n via the resistors 104 _{1 to} 104 _n . The emitters of the transistors 105 ₁ to 105 _n are grounded, and the collectors are connected to the transmission control magnet valves 106 _{1 to} 106 _n . The resistors 104 _{1 to} 104 _n and the transistors 105 _{1 to} 105 _{n form} a transmission control unit 115.

On the other hand, the control terminal of the CPU 103 is connected to the base of the transistor 110 via the resistor 109. The emitter of the transistor 110 is grounded, and the collector is connected to the power supply V _cc via the resistor 111 and the base of the transistor 113 via the resistor 112. The emitter of the transistor 113 is grounded, and the collector of the transistor 113 is connected to the power supply _Vcc through the resistor 114 and also connected to the control terminal of the gate circuit 108. The resistors 109, 111, 112, 114 and the transistors 110, 113 form a gate signal generator 116.

FIG. 2 is a flowchart showing the operation of the CPU 103. The operation of this embodiment will be described below with reference to FIGS. When switching gears (not shown), the switch 101 is first set to the closed state by depressing the clutch plate. In this state, the base of the transistor 110 is grounded via the resistor 109 and the switch 101, so that the transistor 110 is turned off and the transistor 113 is turned on. Therefore, the control terminal of the gate circuit 108 is supplied with low-level signal as a first signal, the gate circuit 108, the control signal V _o which allows passage output state from CP U103 received via the latch circuit 107 Become.

When the change lever is switched to a desired position in this state, the input signal V _i corresponding to the position of the change lever is input to the CPU 103. After determining that the switch 101 is in the closed state (201 in FIG. 2), the CPU 103 outputs and holds the control signal V _o obtained by decoding the input signal V _i (202 in FIG. 2) and repeats this. At the same time, the CPU 103 outputs a latch signal to the latch circuit 107. More, the control signal _{V o} is latched by the latch circuit 107. Since the gate circuit 108 is in a state capable of passing and outputting the input signal, the control signal V _o latched by the latch circuit 107 is supplied to the transistors 105 _{1 to} 105 _n via the gate circuit 108. Therefore, the high-level transistor data signals are inputted only (e.g. transistors ₁₀₅ 1 to 105 ₃₎ is turned on, the other tiger Njisuta _{105 2,} 105 4 to 105 _n in the control signal _{V o} is turned off .

As a result, only the transmission control magnet valves 106 ₁ and 106 ₃ are driven, and the gear is set to the position corresponding to the position of the change lever. After that, when the switch 101 is returned to the open state as the second state by returning the clutch plate, the transistor 110 is turned on and the transistor 113 is turned off, and the control terminal of the gate circuit 108 receives the second signal. High level signal is supplied. In this state, the control signal _{V o} corresponding to the position of the change lever is output from the CPU 103 (203 in FIG. 2), since the gate circuit 108 is in the blocking state, the control signal _{V o} is a gate circuit from CPU 103 108 is not supplied to the transistor motor ₁₀₅ 1 to 105 _n through all the transistors ₁₀₅ 1 to 105 _n becomes off state.

Therefore, it is possible to prevent the occurrence of an abnormal situation such as sudden switching of the gear from neutral to the second speed and a sudden start when the gear is not switched (when the clutch is in contact). According to the present embodiment as described above, so the gate circuit 108 outputs passes the control signal V _o when switching gears addition, since the non-switching gear is configured to so that to shield the control signal V _o Even if the CPU 103 causes an abnormal state such as a runaway or malfunction, it is possible to prevent abnormal gear switching when the gears are not switched.

Further, since the switch 101 is opened and closed by operating the clutch plate, the gear switching operation and the gear abnormal switching can be prevented only by performing the same operation as the manual type vehicle. Because it is possible, it is extremely convenient in operation. In this embodiment, the signal conversion unit is composed of the CPU 103, but it can also be applied to the case of being composed of hardware such as a decoder.

Further, the switch 101 is opened / closed in conjunction with the stepping operation of the clutch plate, but the switch 101 is provided on a change lever or the like and opened / closed by hand. It can also be configured to open and close. Further, the transistors 110 and 113 are provided to prevent the gate circuit 108 from being destroyed due to the application of a hazard to the control terminal of the gate circuit 108. Otherwise, the control terminal of the gate circuit 108 can be connected to the power source _Vcc via the resistor 102.

Although the gate circuit 108 is configured to perform the shielding operation when the switch 101 is in the open state, the gate circuit 108 may be configured to perform the shielding operation when the switch 101 is in the closed state. Further, the switch 101 can be configured not only as a mechanical switch, but also as an optical switch configured by a photo interrupter or the like, a magnetic switch using a Hall element, or the like. The latch circuit 107, by latching a control signal _{V o} output from the CPU 103, but is provided in order to reliably supply the control signal _{V o} to the transmission control unit 115, is output from the CPU 103 If the control signal V _o can be used as it is, the latch circuit 107 is not necessary.

[0016]

[Effect of device]

 The transmission control device of the present invention can prevent the gears from being inadvertently switched due to an abnormal operation of the signal conversion unit when the gears are not switched, and can prevent the occurrence of an abnormal situation such as sudden start. Becomes

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the embodiment of the present invention.

FIG. 3 is a circuit diagram showing a conventional transmission control device.

[Explanation of symbols]

 101 ... Switch 103 ... CPU as signal conversion unit 108 ... Gate circuit as gate unit 115 ... Transmission control unit 116 ... Gate signal generation unit

Claims (1)

[Scope of utility model registration request] 1. A signal converter for converting an input signal corresponding to the position of a change lever into a predetermined control signal and outputting the control signal, and a first state when the gear is switched and a second state when the gear is not switched. Switch, a gate signal generator that outputs a first signal and a second signal when the switch is in the first state and the second state, respectively, and the control signal passes in response to the first signal. Transmission control comprising: a gate unit that outputs and shields the control signal in response to the second signal; and a transmission control unit that switches and controls gears of the transmission based on the control signal output from the gate unit. apparatus.