JPS5939623B2 - automatic transmission control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electro-hydraulic automatic transmission control device used in construction machines such as bulldozers, dozer shovels, and tractor shovels.

Transmissions for construction machinery such as bulldozers, dozer excavators, and tractor excavators, which generally have high power transmission efficiency, are composed of a direct drive multi-stage gear transmission device without a torque converter. Obtaining a speed stage.

Conventionally, an electric-hydraulic automatic transmission control device applied to this type of transmission is disclosed in U.S. Pat. There is something that has been proposed as a "control device using semiconductors."

By the way, in the automatic shifting of the bulldozer and the like, not only forward shifting but also reverse automatic shifting is important, and it is necessary to set the shifting range (range of shifting speed stages) according to the load condition in forward and backward motion.

For example, set the upper and lower limits of the automatic gear shift speed according to forward driving (traveling), forward pushing (excavation), forward heavy digging (for ripping), reverse ground leveling (traveling), reverse traveling, etc. However, the speed stage suitable for the working conditions must be selected.

The present invention has been made in view of the above-mentioned circumstances, and it forms a shift range selection signal that is shared between forward and backward travel from a signal indicating selection of a forward shift range and a signal indicating selection of a reverse shift range, and selects the shift range. It is an object of the present invention to provide an automatic shift control device that determines the upper and lower limits of forward and reverse gear speed stages based on a signal.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 diagrammatically shows a transmission device of an automatic transmission control system with a direct coupling drive system of four forward speeds and four reverse speeds to which the present invention is applied.

The engine 10 drives an engine drive shaft 11.

The engine drive shaft 11 is directly connected to the input shaft 13 of the gear transmission mechanism 21 through a universal joint 15, and as the engine drive shaft 11 is driven, the input shaft 13 of the gear transmission mechanism 21
3 is directly coupled and driven.

The gear transmission mechanism 21 has four forward speeds and four reverse speeds.

The input shaft 13 of the transmission mechanism 21 drives the sun gear 6 of the planetary gear group 9 and the sun gear 29 of the double planetary gear group 27 for switching forward and reverse (R).

The forward gear ratio is obtained from the output of the carrier 8 by using the clutch cylinder F to engage the ring gear 7 of the planetary gear group 9 with the disc brake 25 and fixing it to the transmission mechanism housing 34.

The output of carrier 8 is output from carrier 2 of planetary gear group 27.
8 to the intermediate shaft 14.

For reverse (R) switching, the clutch cylinder R engages the ring gear 30 of the double planetary gear group 27 with the disc brake 31 and fixes it to the transmission mechanism housing 34, thereby obtaining the reverse gear ratio from the output of the carrier 28.

The output of carrier 28 is coupled to intermediate shaft 14 .

The intermediate shaft 14 is connected to the sun gears 39, 40, 41 of the planetary gear group 35, 36, 37 and to the clutch drum 38.

The carrier 42 of the planetary gear group 35 is connected to the ring gear 43 of the planetary gear group 36, and the carrier 44 of the planetary gear group 36 is connected to the ring gear 45 of the planetary gear group 37.
is connected to the transmission mechanism output shaft 12.

To obtain the gear ratio for 1st gear, the ring gear 45 of the planetary gear shaft 37 is fixed to the housing 34 via the disc brake 50 by the operation of the clutch cylinder 1, and to obtain the gear ratio for 2nd gear, the ring gear 45 of the planetary gear shaft 37 is fixed to the housing 34 via the disc brake 50 by the operation of the clutch cylinder 1. 43 is fixed to the housing 34 via the disc brake 47 by actuation of the clutch cylinder 2, and when obtaining the third gear ratio, the ring gear 46 of the planetary gear group 35 is fixed to the disc brake 48 by the actuation of the clutch cylinder 3. This is done by fixing the clutch drum 38 to the housing 34 through the clutch cylinder 4, and when the gear ratio for 4th speed is to be obtained, the clutch drum 38 is fixed to the disc brake 49 by operating the clutch cylinder 4.

In this way, switching between reverse and forward movement and selecting the speed stage are performed by operating the clutch cylinder FR1234.

Table 1 shows the relationship between this selected speed stage and the operation of the clutch cylinder.

A gear 19 for rotation detection is mounted on the input shaft 13, and the number of protrusions on this gear 19 is detected by a speed sensor 20.

The throttle sensor 90 detects the throttle opening of the engine, and provides a signal corresponding to the throttle opening to the electronic control unit 200.

The range select sensor 100 is configured to select reverse second range R1, reverse second range R2, neutral N1 forward third range F.
3. A group of switches connected to the lever 100a that manually selects the second forward range F2 and the forward box range F1, and provides a range selection signal to the electronic control unit 200.

In addition, in the embodiment applied to this bulldozer, ranges R1, R2, N, F3 . F2. The relationship between Fl and the speed stage of the transmission mechanism 21 is configured as shown in Table 2.

The electronic control unit 200 automatically controls the solenoids 81, 82, 83° 84 and SR shown in FIG. 2 based on the signals from the speed sensor 20, throttle sensor 90, and range select sensor 100. do.

Details of this electronic control section 200 will be described later with reference to FIG.

Each clutch cylinder RF1234 has a shift valve group 51 shown in FIG.
It is operated by pilot operating by 2.

Each selector valve 85, 86° 87, 88, 83 is operated by a solenoid 81, 82, 83° S4 SR, respectively.
The relationship with SR is shown in Table 3.

The drive pump 53 is connected to the engine 10 (FIG. 1) by a gear system (not shown), and is driven by the rotation of the engine 10 to suck up the fluid in the reservoir 54 through a suction conduit 56 with a strainer 55. The pump pressure fluid flows through a filter 57 to a branched conduit 59 from conduit 58 and is supplied to a shutoff valve 60.

The purpose of inserting the shut-off valve 60 is to compensate for the pressure in the conduit 58 due to a decrease in the discharge amount of the pump 53 when the engine 10 is idling, and to prevent a shock during gear shifting. This is to prevent the control of the shift valve group 51 from being disturbed.

In addition, as another function, the force of the coil spring 62 generates a force that constantly presses the spool 63 to the closed position.

For example, if the pressure in the conduit 59 drops below the set pressure (this is also true when the pressure in the conduit 64 drops), the force of the coil spring 62 will push the spool 63 to the closed position.

However, if the pump 53 is rotating at the normal rotation speed, the pressure inside the conductor 59 is higher than the set pressure, so the spool 6
3 moves from the closed position to the open position against the force of the coil spring 62 to connect the fluid in the conduit 59 to the conduit 64.

The conductor 64 is connected to each clutch cylinder RF12. This is the supply line that operates 3.

Further, the pressure fluid in the conductor 64 is normally relieved by a modulation relief valve 61, used as lubricating oil for the clutch disk, gears, etc. of the transmission, and is configured to return to the reservoir 54.

The fluid in the conduit 64 passes through the timing pressure valve 70 and then through the conduit 75 to the first gear clutch shift valve 6.
6. A clutch shift valve for 2nd speed 67. A clutch shift valve for 3rd speed 68. A clutch shift valve 69 for 4th speed is supplied.

Further, the fluid in the conduit 75 is supplied to the forward/reverse clutch shift valve 71 in parallel with the shift valve.

As shown in the figure, the timing pressure valve 70 is a valve with an orifice, and when each clutch shift valve operates, and a pressure difference occurs between the inlet conduit 76 and the outlet conduit 75, this is used to switch from position 70A to position 70B. , the vent 74 of the modulation relief valve 61 is drained, and when the pressure inside the conductor 64 decreases and the pressure difference between the inlet conduit 76 and the outlet conduit 75 becomes small, it returns to the position 70A and gradually increases the pressure in the vent circuit 74. .

This also gradually increases the pressure within conduit 75, reducing torque fluctuations that occur during clutch engagement and preventing shift shock.

The fluid in the discharge side conduit 58 of the pump 53 is reduced to a constant pressure by the reducing valve 72, and is supplied to the shift valves 71, 66.67°68.69 through the conduit 73, and the reference pressure for shift valve control is set. It is said that

Since each shift valve 71, 66, 67, 68, 69 is controlled in the same manner, the control of the forward/reverse switching valve 71 will be described below as an example.

The valve 71 has positions 71A and 71B, and a spring 79 constantly pushes the spool to position 71a.

Reference pressure fluid in conduit 73 is supplied to pressure chamber 77 of valve 71 .

On the other hand, the reference pressure passes through the orifice 80 to the spring chamber 78.
It is also supplied to

The fluid in spring chamber 78 is connected to selector valve 81 .

The selector valve 81 is a one-way solenoid valve with two positions, and when the solenoid coil 83 is not energized, the valve 81 is pushed to the closed position by the force of the spring 82, but when the solenoid coil 83 is energized, the valve 81 is pushed to the closed position by the force of the spring 82. Then, the spring chamber 78 of the valve 71 switches to the open position.
The fluid is drained by passageway 84.

Here, since the fluid from the conduit 73 is squeezed by the orifice 80, the pressure in the spring chamber 78 decreases, and the reference pressure in the pressure chamber 77 resisting the spring 79 shifts the spool to position 71B, and the fluid in the clutch cylinder F decreases. The fluid in the conduit 75 is supplied to the clutch cylinder R, and the transmission mechanism 21 is switched to reverse.

Similarly to the shift valve 71, the shift valves 66, 67, 68, and 69 are also controlled by the excitation of the solenoids 81, 82, 83, and 84, and actuate the clutch cylinder 1234.

In this way, by energizing the solenoids 81, 82, 83, and 84 degrees SR, the predetermined speed stage indicated by the gear 3 is selected.

As shown in the figure, the shift valve 69 located at the end of the inner conduit 75 of each shift valve is a 3-way valve (port Ps, port T1, port b) with only port 1'l bt+, and port B). is communicated with the clutch cylinder 4.

A rotating clutch cylinder is used as the clutch cylinder 4.

The shift valve 68 in the preceding stage of the shift valve 69 is a 4-way (port Ps, port T, port a, port b) valve, and when the position is switched by the energization of the solenoid S3, fluid is transferred from port b' to the clutch cylinder 3. The structure is such that fluid is not only supplied to the rotary clutch cylinder shift valve 69 from port a'.

The reason why a valve with such a structure is provided before the shift valve 69 for the rotating clutch cylinder is because the filling time of a rotating clutch is generally longer than that of a fixed clutch, so when shifting from a fixed clutch to a rotating clutch, the power is This is to prevent transmission breakage, which may occur.

In other words, the shift valve 68 is activated by energizing the solenoid S3.
is in the operating position and the clutch cylinder 3 is operated, the solenoid S4 is excited (turned on), the shift valve 69 is switched to the operating position, and the rotary clutch cylinders 4 are operated in parallel (this parallel operation is performed by the shift valve 6).
When the filling of the rotary clutch cylinder 4 (which is made possible by configuring the clutch cylinder 8 as described above) is completed, the solenoid S3 is deenergized (turned off) and the shift valve 68 is switched to the non-operating position.

The hydraulic pressures applied to the fixed clutch cylinder 3 and the rotary clutch cylinder 4 at this time are approximately as shown in FIG. 3.

In FIG. 3, time t indicates the clutch filling time of the rotating clutch cylinder 4;

indicates the parallel operation time of the valves 68 and 69, and the time N indicates the transmission cut-off (power cut-off) time during shifting. This power cut-off time N is important in bulldozers, etc. If the power runs out while the vehicle is running, the vehicle will stop.

Furthermore, the shorter the time N, the smoother the gear shifting is performed.

Control of excitation and demagnetization of these solenoids 83 and 84 is performed by an electronic circuit unit 200, which will be described later.

In this embodiment, the 4-speed clutch cylinder is a rotary clutch cylinder, so the shift valve 68 is used as the valve that supplies fluid to the rear shift valve when in the above operating position, but the other clutch cylinders are rotary clutch cylinders. When configured with a cylinder, if a valve with the above structure is used before the rotary clutch valve, parallel operation with the rotary clutch cylinder can be performed and power failure can be prevented.

However, if the first speed clutch cylinder 1 is a rotary clutch cylinder, the first speed shift valve 66 uses a valve having the above structure.

FIG. 4 shows an embodiment of the electronic control section 200 in the electro-hydraulic automatic transmission control system of the present invention.

Although the power supply circuit is not shown, a reference voltage of 12 volts DC is supplied to each circuit from a 24-volt DC vehicle battery through a constant voltage circuit.

As shown in FIG. 5, the speed sensor 20 includes a high frequency oscillation circuit 201 including a pickup coil, a detection circuit 203 connected via an output line 202 of the high frequency oscillation circuit 201, and a line 2 on the output side of the detection circuit 203.
04, and a rectangular wave shaping gate 205 connected through 04.

The speed sensor 20 outputs the same number of pulses as the number of protrusions to the line 206 according to the proximity of the protrusions of the gear 19.

This pulse has a voltage waveform as shown in FIG.

As a result, a rectangular wave pulse signal having a period proportional to the rotational speed of the torque converter output shaft 13 is outputted from the speed sensor 20 and inputted to the rotational speed comparison circuit 92 via the line 206.

The throttle sensor 90 is composed of a group of multi-contact switches as shown in FIG.

For such a switch, Japanese Patent Application No. 48-130129
It is appropriate to use a switch described in the specification of a throttle opening detection device for a vehicle equipped with a diesel engine.

In principle, this switch is a movable contact 9 connected to a movable piece 90f that operates in accordance with the throttle opening of the engine 10.
0e are fixed contacts Pa and Pb.

It is selectively engaged with Pc and Pd.

Fixative solution rea. Pb, Pc, and Pd are grounded,
A positive voltage (+12V) is applied to the output lines 90a, 90b, 90c, and 90a through a resistor R8 and a diode D, as will be described later.

(shown in FIG. 8), a low level signal is generated in the output lines 90a-90d when the fixed contacts 90a-90d are engaged in accordance with the throttle opening.

For example, when the throttle opening is 0 (idle), a signal is generated on line 90a, and when the throttle opening is slightly above idle, a signal is generated on line 90b, and the throttle opening is changed from half to fully open. Time is line 90
A signal is generated on line 90d, and when the throttle opening is at the maximum opening (detent) above full open, a signal is generated on line 90d.

The output of the throttle sensor 90 is supplied to a throttle position detection circuit 91.

The throttle position detection circuit 91 has input lines 90a to 90.
It includes a latch circuit that latches the signal d, and a pulse generation circuit that releases the latch circuit, and sends a signal corresponding to the throttle opening degree to lines T'H8 to TH3 based on the signals on input lines 90a to 90d. Output.

FIG. 8 shows an example of details of this throttle position detection circuit 91.

The latch circuit 910 includes D-latches 910a, 910b, 9
10c, input lines 90a, 90b, 90
The low level signal generated at the inverter 911a91
1b and 911c are inverted and temporarily stored, respectively.

A pulse generating circuit 912 generates a pulse signal that sets the memory of the launch circuit 910.

The signals on input lines 90a-90d are applied to a NAND circuit 914 via a NOR circuit 913.

(This signal is designated as Vl.

) Signal ■1 is connected to the input line 90a~ as shown in Figure 9a.
When no signal is generated on input line 90d (all at high level), it is low level, and when a signal is generated on any of the input lines 90a to 90d (when it becomes low level), it becomes a pulse signal that rises to high level.

On the other hand, the output (signal V,) of the OR circuit 913 is applied to the other input terminal of the NAND circuit 914 via an RC circuit consisting of an inverter 915, a resistor R, and a capacitor C.
This signal is referred to as ■2).

As shown in FIG. 9, the signal (2) is high when the signal (2)1 is low, and when the signal (2) rises to high, it becomes a signal whose potential decreases as the capacitor C discharges.

The purpose of the diode D inserted in parallel with the resistor R is to prevent the discharge potential of the capacitor C from affecting the signal 1.

The output of NAND circuit 914 becomes an output signal of pulse generation circuit 912 via inverter 916.

(This signal is designated as V3) The signal V3 is a pulse signal generated at the rising edge of the signal 1 as shown in FIG. 9C.

In this way, from the pulse generation circuit 912, the lines 90a to
One pulse is output every time a signal occurs on any of 90d.

The pulse signal from the pulse generation circuit 912 is sent to the launch circuit 9.
10 latches 910a, 910b, 910c, unstoring each latch and causing new signals appearing on lines 90a-90c to be stored in the corresponding latch.

In this way, each time the throttle opening changes, the latch circuit 91
The memory of 0 is rewritten.

The signal on the output line 90d corresponding to the maximum throttle opening (detent) is not stored in the latch circuit 910, but is directly input to the rotation speed comparison circuit 92 as the throttle signal TH3 via the inverter 911d.

Also, the signal on line 90d is sent to inverter 911d.

It becomes one input of the NAND circuit 918 via the input signal 917 .

The other input of the NAND circuit 918 is a launch 910c that stores a signal on a line 90c corresponding to the throttle opening below the maximum throttle opening, that is, from throttle half to full.
The output of is added.

By the way, the lines 90c and 9Qd are connected through a diode Dd as shown in the figure, and when the throttle opening reaches the maximum and a signal (low level) is generated on the line 90d, the signal on the line 90c also becomes low level due to the diode Dd. The memory of latch 910c is configured not to be released.

Therefore, when the throttle signal TH3 is generated, the output of the NAND circuit 918 is bi-level ("1") due to the action of the inverter 917, but as soon as the output of the throttle sensor 90 changes from line 90d to line 90c, the NAND circuit The output of 918 is set to low level.

The output of this NAND circuit 918 is inverted by an inverter 919 and applied to a comparison circuit 92 as a throttle signal TH2.

Here, a latch for storing the signal from the throttle sensor 90 is provided corresponding to the lines 90a to 90c, and the signal on the line 90d that occurs at the maximum throttle opening (detent) is set as the throttle signal TH3 without being latched, and the diode Dd , the throttle signal TH is
3 is made to occur only at the maximum throttle opening in order to prevent hysteresis from occurring in the throttle signal.

Further, the outputs of latches 910a and 910b that store the signals of output lines 90a90b of throttle sensor 90 are applied to rotation speed comparison circuit 92 as throttle signals THo and TH1, respectively.

The latch circuit 910 is 5CL4042A type or R manufactured by Solid State Scientific.
It is preferable to use an integrated circuit such as the CD4042A model manufactured by CA.

The rotation speed comparison circuit 92 includes an 8-bit binary counter 920.
, a shift-up comparator 921, a shift-down comparator 922, a diode matrix 923 that inputs throttle signals THo to TH3 and encodes them into binary data corresponding to a predetermined set rotation speed, and a diode matrix bias resistance group 924. Equipped with.

The binary counter 920 can be, for example, an integrated circuit of the type 5CL4520A manufactured by Solid State Scientific, and the comparators 921.92
2, for example, Motorola MC14585A type 4.
It is possible to use a cascaded combination of bit magnitude comparators to form 8 bits.

Clock pulse generation circuit 93 periodically provides a reset pulse to counter 920.

Therefore, the generation interval of this reset pulse is determined by the counter 920.
The counter 920 counts the number of pulses supplied from the speed sensor 20 during this reference time.

The count output of counter 920 becomes one input of comparators 921 and 922.

A diode matrix 9 is connected to the other input (B) of the shift-up comparator 921 and the shift-down comparator 922.
The value preset in 23 is the throttle signal T) (0 to
It was added in response to the outbreak of TH3.

The rotation speed comparison circuit 920 calculates the rotation speed of the transmission input shaft 13 (
A shift up pulse or a shift down pulse is generated according to a shift pattern as shown in FIG. signal or torque converter lockup release signal.

In FIG. 10, a line 931 indicates a downshift line, and a line 932 indicates an upshift line.

The diode matrix 926 encodes the input throttle signals TH1 to TH3 into values corresponding to a predetermined set rotational speed according to the shift pattern of lines 931 and 932 as shown in FIG. It is composed of

That is, when the throttle opening is at the minimum opening (idle) and the throttle signal THo is generated, the downshift rotation speed DRo1 and the shift up rotation speed UR8 are set.
When the throttle signal TH1 is generated, the shift-down rotation speed DR and shift-up rotation speed UR1 are set, and when the throttle signal TH2 and throttle signal THφ5 are generated, the shift-down rotation speed is set to the same rotation speed DR as above. However, the upshift rotation speed is determined by the throttle signal T.
Rotation speeds UR2 and UR3 are set according to H2 and TH3.

By the way, in this automatic transmission control device, the throttle opening is at the idle position, that is, the throttle signal TH
The shift-up rotational speed URO when "o" is occurring is set to be higher than the high idle rotational speed of the engine.

Therefore, when the throttle opening is idling, the shift-up does not occur at normal engine speed, but the shift-up is performed only when the engine becomes overspeed to protect the engine.

Therefore, if you set the throttle opening to the minimum opening (idle), you can set the throttle opening even when the rotation speed is high due to a light load such as when exiting a vehicle or when a vehicle is being pushed by a bumper such as a motor scraper. It is not upshifted up to the high rotational speed URo, and is held dynamically at low speed.

The outputs of the comparators 921 and 922 are applied to AND circuits 94 and 95, and the reset pulse from the clock pulse generation circuit 93 is applied to the other input of the AND circuit 94 and 95.
Join via 30.

Therefore, each shift pulse is taken out from comparators 921 and 922 via AND circuits 94 and 95 in synchronization with the counting reference time of counter 920.

In this way, since the rotation speed comparison detection in the rotation speed comparison circuit 92 is performed every reference time of the counter 920, the counting of the number of input pulses from the speed sensor 20 in the counter 920 is averaged within the reference time, and rotation unevenness is This is to make the response slower.

The upshift comparator 921 produces an output when the current rotational speed input from the counter 920 becomes greater than the set value input (2) from the diode matrix 923 (A2B).

This output is supplied via an AND circuit 94 to a line 94a as a shift up pulse.

The downshift comparator 922 produces an output when the current rotational speed input from the counter 920 becomes smaller than the set value input (B) from the diode matrix 923 (A≦B), and this output is sent to the AND circuit 95. The signal is then supplied to line 95a as a downshift pulse.

The range select sensor 100 is a select lever 100a
FIG. 11 shows a group of switches operated by the switch group, and its contact configuration is shown in FIG.

The contact point of each switch is at each position 1 of the select lever.
．． 1'''Forward 1st, range F1 (forward 1st speed), forward range F2 (forward 1st to 2nd speed automatic), forward 3rd range F3
(forward 1st to 4th speed automatic), neutral N, reverse 2nd range (backward 1st to 4th automatic), and reverse lunge (backward 1st speed).

An automatic gear shift range is selected by operating the select lever 100a, and when each switch of the range select sensor 100 is turned on or off, a signal based on this on/off is sent to line 1.
The signal is input to the range select detection circuit 107 via signals 01 to 106, and the upper limit speed stage for upshifting is set.

The range select detection circuit 107 uses a memory circuit 1 called a D latch to prevent malfunctions due to input signal chattering.
08 is used.

It is appropriate for this circuit 108 to use an integrated circuit 5CL4042A type or CD4042A type having the same configuration as the latch circuit 910.

The signal on line 101 corresponding to the second forward range F1 and the signal on line 106 corresponding to the second reverse range R1 are applied to the memory circuit 108 via the OR circuit 101a.

Line 103 corresponding to the third forward range F3 and the second reverse range
The signal on line 105 corresponding to range R2 is OR circuit 1
03a to the memory circuit 108.

Further, the signal on line 102 corresponding to the second forward range F2 and the signal on line 104 corresponding to neutral N are directly applied to the memory circuit 108.

Differential pulse generation circuit 109 generates a pulse in response to changes in the signals on lines 101 to 105, applies this pulse to a latch in memory circuit 108 via line 110,
Let this reset.

For example, if the range select command moves from the forward cylinder lunge F1 to the second forward range F2, one pulse is generated from the differential pulse generation circuit 109, the memory in the memory circuit 108 is cleared, and the signal on the line 102 is renewed. Rewrite as a signal.

That is, when the select lever 100a is switched from range F1 to range F2, the range F1 signal is held until the range F2 detection switch is turned on after the range F1 detection switch is turned off in FIG. 11, and the lever 100a is moved. The configuration is such that the output of the memory circuit 108 is not interrupted even during the process.

The output signal IR of the memory circuit 108 indicating that range F1 or range R1 has been selected is output from the flip-flop 11.
1 reset input.

Further, the output NR of the memory circuit 108, which occurs when neutral is selected, is applied to the reset input of the flip-flop 111.

Therefore, the flip-flop 111 is in the range F1 or R1.
is set when is selected, and reset when neutral is selected.

The reset output of this flip-flop 111 is applied to a NAND circuit 124, which will be described later, and is used to indicate the lower limit of downshift.

The range select command IR and the set output IR of the flip-flop 111 are applied to an AND circuit 112, and the signal on its output line 116 is supplied to the diode master (IJ) 114 of the range select circuit 113.

The range select command 2R is applied to the diode matrix 114 via line 117 and is applied to the select lever 100.
When a is set to range F3 or R2, the range select command 3R output from the memory circuit 108 is applied to the diode master (IJ) 114 via a line 118.

The diode matrix 114 sets the upper limit of the speed stage in automatic shifting in accordance with the position of the range select lever 100a.

In the case of the automatic transmission with four forward speeds and four reverse speeds of this embodiment, the forward cylinder lunge F1 of the range select lever 100a has an upper limit of the first forward speed, and the upper limit of the second forward range F2 is the second forward speed. The upper limit of the third forward range F3 is 4th forward speed, the upper limit of the second reverse range R2 is 4th reverse speed, and the upper limit of the reverse cylinder lunge R1 is 1st reverse speed.

Therefore, in response to range select command IR on line 116, range select command 2R on line 117, and range select command 3R on line 118, each diode in matrix 114 is connected to produce an encoded output as shown in the table below.

That is, in response to the commands IR2R and IR3R, a binary code corresponding to the highest speed stage of each range, 1st forward speed, 1st reverse speed, 2nd forward speed, 4th forward speed, or 4th reverse speed is output.

In FIG. 3, the cathode of the diode is connected to line 116.
117 or 118 and diode matrix 1
14 is configured so that a positive voltage is applied to each line 116 117 via a pull-up resistor 114a.
Inverters 116a, 117a, and 118a are inserted into 118.

However, instead of providing an inverter, the resistor 114a may be grounded and a diode may be provided at the location "1" in Table 4.

Binary code A output from diode matrix 114.

, AI, A2, A3 (A) is comparator 1
26.

A comparator 126 counts shift up pulses generated on line 94a and downshift pulses generated on line 95a, which will be described later, and receives a binary code B representing the current speed stage.

, B1. B2. A signal from automatic shift counter 138 outputting B3(B) is added and compares input A from diode matrix 114 with input B of counter 138.

In this comparison, if the input A from the diode matrix 114 is larger than the input B from the counter 138 (A>B), the signal output from the line 131 outputs the signal "1" to the output line 131. , indicates that the current speed stage (B) is lower than the upper limit speed stage (5) set by the range select lever 100a, and this signal is applied to the AND circuit 139, and other conditions of the circuit 139 are This makes it possible to generate an "up pulse" when

Further, when the input A of the comparator 126 is smaller than the input B (A<B), a signal "1" is output to the output line 132.

This indicates that the current speed gear (B) is higher than the upper limit speed gear (5) set by the lever 100a, and the signal "1" on the line 132 is applied to the AND circuit 145 to perform a "forced downshift". ask for something to be done.

The signal on line 132 is also inverted by an inverter 143 and applied to an AND circuit 146 via line 144.
AND circuit 14 on the condition that it is not "forced downshift"
6 is enabled, and in response to a signal from line 95a, "
"shift down pulse" is given.

In addition, as the comparator 126, for example, Motorola (
Motorola) MC14585 series 4
A bit comparator integrated circuit may be used.

The automatic shift counter 138 is a reversible counter with a preset input A.

. The contents of the counter are preset by the preset data given to Bo, co, and Do, and the preset values are output from the binary 4-bit output lines 127, 128, 129° 130, and the initial value of the automatic gear is determined. It looks like this.

That is, preset human power A.

- If preset data corresponding to decimal number 2 is added from Do, the initial value of the gear stage is 2, forward or reverse 2nd speed is specified when starting, and preset manual A
.

If the preset data corresponding to the decimal number 1 is added from -Do, the initial value of the gear position is 1, and the first forward speed or the first reverse speed is specified at the time of starting.

Preset input A like this.

By presetting -Do to a desired value, the initial value of the gear position can be arbitrarily determined.

However, in this embodiment, since a transmission with 4 forward speeds and 4 reverse speeds is used, the preset manual power A is used only for starting in 1st speed when moving forward or backward.

Preset data corresponding to decimal number 1 is added to -Do, and the initial value of the gear position is set to 1st speed.

Of course, depending on the number of gears or the purpose of use, the initial value of the gear can be preset to a desired value and the vehicle can be started from the desired gear.

The preset data added to -Do may be configured to be changeable based on the output of the range select sensor 100, and the initial value of the speed change may be changed in accordance with the selected range.

The preset data added to the preset manpower status ~Do is preset to the automatic shift counter 138 in the following manner.

When the range select lever 100a is in the neutral N position, the range select sensor 100 outputs a signal to the line 104, and since the flip-flop 133 is reset by this signal, the signal on the set output line 134 of the flip-flop 133 The automatic shift counter 138 is cleared by.

(See FIG. 12C) At this time, the outputs of the counter 138 (lines 127-130) are all 10''.

When the range select lever 100a is switched from neutral N to the third forward range F3 or the second reverse range R2, the range sensor 100 is switched.

A signal is output to line 103 or line 105, and flip-flop 133 is set by one of the above signals via OR circuit 103a.

The signal on reset output line 135 of flip-flop 133 is applied to a differentiator circuit 136 which applies a differentiated pulse as shown in FIG. 12 to the load input of automatic shift counter 138.

The pulse from the differentiating circuit 136 causes the counter 138 to be loaded with binary preset data '0001'' (see FIG. 12C) corresponding to the decimal number 1 that has been added to the preset manual input value ~Do.

This causes the output of counter 138 (lines 127-13
0) is preset to the value '0001'' (first
(See Figure 2C).

Thereafter, when an up pulse is applied to the counter 138 from the AND circuit 139 (FIG. 12 e), the contents of the counter 138 are added up, and when a down pulse is applied via the AND circuit 140 (FIG. 12 f), the contents of the counter 138 are added. Contents are subtracted.

By the way, in the case of upshifting, it is sufficient to increase the contents of the automatic shift counter 138 by the upshifting pulse given from the upshifting comparator 921 via the AND circuit 94 and the line 94a. There is an upper limit to the speed range that can be used.

For this reason, an AND circuit 139 for automatic shift up is provided at the up input of the automatic shift counter 138, so that only the necessary up pulse is inputted to the up input of the automatic shift counter 138.

An example of the input and output of the AND circuit 139 is shown in FIG.

As mentioned above, the signal on the line 131 is '1'' unless the range select upper limit set by the range select lever 100a is reached.

For example, as is clear from the above-mentioned cloth 4, when the lever 100a is in the range F1 or R1, the signal on the line 131 is 10' when the transmission 21 is in the first forward speed or the first reverse speed.
Therefore, if Leno←100a is in range F2, line 131 becomes 10" when the forward speed is 2nd, and lever 10
If 0a is in range F3 or R2, line 131 becomes 10'' when the vehicle is in 4th forward speed or 4th reverse speed.

Thus, the signal on line 131 is related to the range select upper limit, and this signal is applied to AND circuit 139.

Further, a signal from the upshift prohibition time setting circuit 152 is applied to the AND circuit 139 so that the upshift prohibition time setting circuit 152 does not enter the upshift control pulse while the transmission 21 is in a transient state during automatic shifting.

The upshift disabled time setting circuit 152 is a type of timer circuit, and when a shift detection pulse is applied via the OR circuit 149, it generates an output "□N" for the time Tx, and inhibits the operation of the AND circuit 139.

It should be noted that the hold signal output is 10'' by manual operation when the automatic shift hold is performed, and is 11'' when the shift is not held.

The count up or down of the counter 138, which sets the hold signal to '0', is interrupted and the count value at that time is held.

In the case of a downshift, the automatic shift counter 138 is operated by a downshift pulse applied from the downshift comparator 922 via the AND circuit 95 and line 95a. Circuit 145.146, OR circuit 147,
An automatic downshift gate circuit composed of an AND circuit 140 is provided.

An example of the input and output of this automatic shift down gate circuit is shown in the first example.
Shown in Figure 1.

The AND circuit 145 is a circuit related to "forced downshift", and in particular, one example of input/output is shown in FIG. 14a.

For example, when the lever 100a is set to the third forward range F3 and the vehicle is traveling at the fourth forward speed, the lever 100a
When switching from range F3 to forward second range F2,
It is necessary to forcibly downshift sequentially, such as 4th forward speed → 3rd forward speed → 2nd forward speed.

In this case, as described above, the signal on the output line 132 of the comparator 126 becomes 11", and the manual hold signal H8
If also 11", the AND circuit 145 becomes operational,
A forced downshift is immediately performed.

When performing a normal downshift, the signal on line 132 is 10'' and the output of inverter 143 is X1''.

At this time, if the manual hold signal H8 is 1", the AND circuit 146 becomes operational, and the circuit 146 generates a pulse at the timing of the shift down pulse applied to the AND circuit 146 from the line 95a (see FIGS. 14a and 14b). )
.

The outputs of AND circuits 145 and 146 are input to AND circuit 140 via OR circuit 147.

This AND circuit 140 includes a shift disabled time setting circuit 15.
1, and a downshift lower limit signal from the NAND circuit 124 is added thereto.

The non-shift time setting circuit 151 is a timer-like circuit having an operating time of time Ty, and outputs a signal 0" having a width of time Ty during gear shifting, thereby securing the operating time for one downshift.

The NAND circuit 124 is supplied with range select command signals 2R and 3R via the OR circuit 123, the reset output of the flip-flop 111, and a signal on a line 154 corresponding to the first speed gear from a decoder 153, which will be described later. , when the selected range is F2, F3 or R2, the output signal becomes 10'' when a signal is generated on the output line 154 of the decoder 153, which limits the lower limit of downshifting.

Therefore, in this case, the lower limit of the downshift is the first speed.

The input/output relationships of the AND circuit 140 when the conditions of the NAND circuit 124 are satisfied are shown in FIGS. 14a, b, and c.

Since the output of the automatic shift counter 138 is expressed in binary numbers, a decoder 153 is provided to convert it into a decimal number corresponding to each speed stage.

Decoder 153 outputs lines 127 to 138 of counter 138.
130 binary signals are decoded into four output lines 154 to 157 corresponding to the first to fourth speeds.

As the decoder 153, for example, a solid state
Scientific (So-1id 5tate 5
A type 5CL4028A integrated circuit manufactured by Scientific Corporation can be used.

Table 5 shows the relationship between the binary input and the decimal output of the decoder 153.

In Table 5, the figure number of the line where 11" occurs in the output line is written in the output line.

Note that by increasing the number of output lines of the decoder 153, the present invention can also be applied to a 6-speed or 10-speed automatic transmission.

The automatic shift detection pulse generation circuit 146 is, for example, a circuit such as a differentiating circuit, and inputs the signal of the lowest digit (line 127) of the automatic shift counter 138, detects a change in the value, and detects a change in the value from 11" to 10" or A shift detection pulse is output when the signal changes from '0'' to 11''.

The manual shift detection pulse generation circuit 150 inputs the output of the differential pulse generation circuit 109 and inputs the output of the differential pulse generation circuit 109 to the range selection sensor 100.
Outputs a gear shift detection pulse when the switch is switched.

The outputs of both circuits 148 and 150 are applied to shift disabled time setting circuits 151 and 152, respectively, via an OR circuit 149.

Unable to shift time Ty, Tx (see Figures 13 and 14)
The time required for one downshift operation and one upshift operation of the transmission 21 is taken into consideration.

Output line 15 corresponding to 3rd and 4th speed of decoder 153
Signals 6 and 157 (see FIGS. 15a and 15b) are applied to an AND circuit 161 via an OR circuit 160.

A shift up pulse (see FIG. 15C) from the line 94a is applied to the other input of the AND circuit 161.

Therefore, the AND circuit 161 is connected to the line 156 or 167.
When a shift-up pulse is applied while a signal is being generated in , a signal '1'' is outputted and applied to the timer circuit 162.

The timer circuit 162 is composed of an off-delay timer, and when the input signal rises to ``1'', the output immediately becomes 1'', but when the input signal falls to ``0'', the output does not immediately become 10''. It becomes '0'' after a delay of a predetermined time T.

(See FIG. 14) The output of this timer circuit 162 is applied to an OR circuit 163 together with the signal on the output line 156 of the decoder 153, and is outputted to a line 156a as a signal corresponding to the third speed.

In this way, the signal on line 156a will not become 0'' even if the signal on line 156 is cut off, as shown in FIG. 15e.
"1" is held for the operating time T of the timer 162.

Therefore, signals are simultaneously output to lines 156a and 157 for the operating time T of this timer circuit 162.

At the L roller, the signal on the line 156a and the signal on the line 157 become energizing signals for the solenoid S3 and the solenoid S4, as described later, and control the valves 68 and 69 as described above to move the fixed clutch cylinder 3 to the rotating clutch cylinder 4.
Since the rotating clutch cylinder 4 described above is switched to
If the operating time T of the timer circuit 162 is set to the filling time t (Fig. 3), the fixed cylinder 3 and the rotating cylinder 4 will operate in parallel for only the time T by the valve 6869, and the rotating clutch will be switched from the fixed clutch 3 to the rotating clutch. It is possible to prevent power transmission failure (power failure) when switching to 4, and to perform smooth upshifts.

In the above explanation, the case where the 4th speed clutch is configured as a rotary clutch is shown, but when the 1st speed clutch is configured as a rotary clutch, the 1st gear valve 66 (Fig. 2) is used as described above. A valve similar to valve 68 may be used, and the control circuit may be configured as shown in FIG.

In FIG. 16, the same signals as in FIG. 4 indicate the same configuration.

The signals on output lines 154 to 155 of decoder 153 are applied to AND circuit 161 via OR circuit 160.

A shift down pulse, which is the output of the OR circuit 147, is applied to the other input of the AND circuit 161.

The output signal of the AND circuit 161 is passed through a timer circuit 162 to an OR circuit 16 to which the signal on the line 155 is added.
Added to 3.

Therefore, the signal on line 155a does not become 10'' even if the signal on line 155 is cut off, but becomes 10'' after being delayed by the operating time T of timer circuit 162.

If the 1st gear clutch is engaged by the rotary clutch in this way, when downshifting from 2nd gear to 1st gear, controlling the 2nd gear clutch to disengage after a delay of the filling time of the rotary clutch will prevent power loss. This allows for smooth gear shifting.

In addition, if a rotating clutch is used for anything other than the 1st or 4th gear clutch, configuring the preceding clutch to disengage after the filling time of the rotating clutch will prevent power loss when switching from a fixed clutch to a rotating clutch. can do.

The signal on the output line 154 155157 of the decoder 153 and the signal on the output line 156a of the OR circuit 163 are applied to am-m paths 172, 173, 174° 175, respectively.
The output line 1 of the range select sensor 100 indicates that the second reverse range R2 is selected in the AND circuit 176.
The set output of flip-flop 158 is applied via line 159, set by the signal on output line 104 indicating that neutral range N has been selected.

The output of the neutral interlock circuit 179 is added to the other inputs of each AND circuit 172-176.

The neutral interlock circuit 179 prevents a solenoid selection signal from being output unless the range select lever 100a is set to the neutral position N when a key switch (not shown) for starting the engine 10 is turned on. This is a circuit designed to do this.

For example, a memory circuit (not shown) is set so that the output line 170 becomes 10" when the engine start key switch is turned on, and the range select sensor 100
The circuit configuration is such that when a detection signal of the neutral position N is generated on the neutral position detection line 104 from the neutral position detection line 104, the memory circuit is reset and the output line 170 is set to 11''.

In addition, the neutral interlock circuit 179 is configured so that the output becomes 10" when the engine is overloaded, and no signal is output from the AND circuits 172 to 176 unless the lever 100a is set to neutral N when the engine is overloaded. It can also be configured as

Since the interlock circuit 179 is constructed as described above, the output is 11" during normal operation.

Therefore, during normal operation, the AND circuits 172 to 176 are open, and the lines 154155 156a 157 1
The signals 59 are applied to the solenoids driving amplifiers 182 to 185, respectively.

The solenoid drive amplifiers 182-185 are constructed of, for example, Darlington-coupled switching transistors, and the outputs of the amplifiers 182-185 energize the corresponding solenoids 81, 82, 83°84 and SR.

Each solenoid 81.82,83,84. SR is the selector valve 85 8 in the fluid circuit of FIG. 2 as described above.
6 87 88 83, and pilot operates the shift valve group 51 to control each clutch cylinder.
Activate νF.

Solenoids 81-SR and clutch cylinders 1-4. R
, F and the speed stage are as shown in Table 3 above.

As explained above, since the present invention has the above configuration, automatic gear shifting of multiple forward speeds and multiple reverse speeds is possible.
Automatic gear shifting allows the appropriate speed stage to be automatically selected not only in forward motion but also in reverse motion.

[Brief explanation of the drawing]

Fig. 1 is a schematic structural explanatory diagram showing an embodiment of the present invention applied to an automatic transmission with 4 forward speeds and 4 reverse speeds, and Fig. 2 shows an example of fluid pressure control related to the same embodiment. The control circuit diagram, FIG. 3 is a graph showing the oil pressure applied to the fixed clutch cylinder and the rotating clutch cylinder when switching from the fixed clutch to the rotary clutch in the same embodiment, and FIG. 4 is a graph of the electronic control unit in the same embodiment. FIG. 5 is a block diagram showing an example of the speed sensor in the same embodiment. FIG. 6 is a graph showing an example of the output pulse of the speed sensor in FIG. 5. FIG. 7 is the same embodiment. FIG. 8 is a circuit diagram showing details of the throttle position detection circuit, FIG. 9a is a circuit diagram showing an example of a throttle sensor in FIG.
b and c are the signals shown in FIG. ■2. A graph showing an example of V3, Fig. 10 is a graph showing an example of a shift pattern consisting of the correlation between the throttle opening and the speed change mechanism input shaft rotation speed, and Fig. 11 shows an example of the select sensor in the same embodiment. A circuit diagram, FIG. 12 is a timing chart showing an example of input/output signals of the automatic shift counter shown in FIG. 4, and FIG. 13 is a logic circuit that provides an up pulse input to the automatic shift counter shown in FIG. FIG. 14 is a timing chart showing an example of the operation; FIG. 15a is a timing chart showing an example of the operation of the logic circuit that provides a down pulse input to the automatic shift counter shown in FIG. 4; b, c, d, and e are timing charts showing an example of the operation of a circuit that delays and disconnects a signal to a fixed clutch in the preceding stage of a rotary clutch in the same embodiment, and FIG. 16 is a main part of an electronic control unit according to the present invention. FIG. 1.2,3,4. F, R... curved clutch cylinder, 81
．． 82, 83, 84. SR・・・Solenoid, 1
0...Engine, 20...Speed sensor, 21...Multi-stage gear transmission mechanism, 51...
...Shift valve group, 52...Selector valve group, 90...Throttle sensor, 91...
... Throttle position detection circuit, 92 ... Rotation speed comparison circuit, 100 ... Range select sensor, 107 ... Range select detection circuit, 113
...Range select circuit, 126...
Comparator, 138... Automatic shift counter, 162... Timer circuit, 200...
Electronic control section.

Claims (1)

[Claims] 1. A logic circuit that forms a shift range selection signal shared by forward and reverse travel by appropriately ORing a signal indicating selection of a forward shift range and a signal indicating selection of a reverse shift range; A memory circuit that determines and stores whether a forward gear range or a reverse gear range is selected based on the history of generation of signals indicating selection of each gear range; and a memory circuit that determines and stores whether a forward gear range or a reverse gear range is selected; and a gear shift upper and lower limit setting circuit that sets upper and lower limits of the gear gear based on the selection signal, and the upper and lower limits of the forward and reverse gear gears are set according to the set values of the gear gear upper and lower limit setting circuit. An automatic transmission control device that limits forward movement and reverse movement according to the output of the memory circuit.