JPH0534552B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control device for an automobile transmission equipped with a synchromesh mechanism. It is particularly suitable for use in control devices for transmissions for large automobiles.

[Conventional technology]

It is known to use a pressure cylinder to change gears of a transmission by remote control or automatic control. In conventional pressure cylinders that utilize air pressure, for example, the air pressure of the pressure cylinder is controlled by valve operation, and the force acting on the speed change lever is approximately constant over the period of movement of the piston.

On the other hand, transmissions are equipped with a synchronized mesh mechanism, and when the driver manually operates the gear shift lever, the shift lever is moved with a weak force at the stroke position where the synchronized mesh operates, and the gears are moved. At the stroke position where the gears engage, a strong force is used to move the gear shift lever. If this is mechanically operated with a constant force, unreasonable force is applied to the synchronized mesh mechanism, which may cause so-called gear noise.

[Problem to be solved by the invention] When designing an automatic transmission for a large vehicle using power shift, the inventor conducted various tests and found that the above-mentioned gear noise could be eliminated by weakening the force of the pressure cylinder. Although it is possible to prevent this from occurring, the time required to change gears will become longer and this will impede smooth operation.
On the other hand, it was found that if the force of the pressure cylinder was increased, gear noise would occur and unreasonable force would be applied to the synchronized mesh mechanism, causing the gears to wear out faster.

The present invention is an improvement on this, and an object of the present invention is to provide a control device for a transmission in which the time required for shifting is short and the synchromesh mechanism is smoothly operated.

[Means for solving problems]

The present invention includes a pressure cylinder, a piston that moves within the pressure cylinder, and a piston rod that is connected to the piston.A lever of a transmission is connected to the piston rod, and the pressure cylinder has a movement range of the piston. In a transmission control device, the transmission control device includes a valve device installed on both sides of the pressure cylinder for inflowing and discharging fluid pressure into and out of the pressure cylinder, and a control circuit including a microcomputer that controls the valve device. The control circuit includes an engine rotational speed detection means and a vehicle speed detection means for detecting a vehicle speed, and the control circuit moderates the passage speed of the fluid passing through the valve device for a predetermined period of time in a switching transient state of the transmission. The control means is characterized in that the control means includes means for taking in the detection outputs of the two detection means and calculating the predetermined time.

[Effect]

By controlling the microcomputer, the time required for changing the transmission can be appropriately controlled.

In particular, when vehicle running data and engine data are taken into account, when the driver gives a command to the control circuit to convert the transmission, the engine rotational speed, which is input to the control circuit and indicates the running state of the vehicle, The input value of the vehicle speed is compared with the vehicle's preset gear shift characteristics, and the load on the synchronizer mechanism, which is a transient state in which the transmission switches to the next gear, is adjusted to correspond to this load. The predetermined length of time for weakening the driving force of the pressure cylinder that drives the transmission is calculated. The pressure cylinder has valve devices on both sides of the piston's movement range that allow fluid to flow into and out of the cylinder, and is configured to weaken the driving force of the piston by slowing down the fluid velocity passing through these valve devices. By controlling the valve device for the above-mentioned predetermined period of time, the transmission can be controlled so as not to put strain on the synchromesh mechanism.

〔Example〕

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of essential parts showing one embodiment of the present invention. In FIG. 1, the lever unit LU, which is the switching means of the transmission operated by the driver, is composed of an operating lever and a multi-contact switch section (not shown) that is interlocked with the operating lever. Engine E has a rotational speed sensor SS1, and transmission D has a vehicle speedometer SM.
A speed sensor SS2, a shift unit SU for switching gears, and a gear position sensor GS attached thereto are provided, respectively.

This shift unit SU is connected to a pressure cylinder C via a piston rod PR and a lever LV. At both ends of this pressure cylinder C, two solenoid valves SL1, SL2 and one exhaust valve are installed as valve devices.
EV will be provided.

Outputs of lever unit LU, rotational speed sensor SS1, speed sensor SS2, and gear position sensor GS, solenoid valves SL1 and SL2, and exhaust valve EV
The inputs to are respectively connected to the control circuit CP via input/output interfaces I/O.

When the piston of the pressure cylinder C operates according to a command from the lever unit LU, as shown in Figure 2, the gears that are currently meshing become neutral in the section, synchronized meshing occurs in the section, and the next gear in the section becomes neutral. The second gear is meshed with the second one. T1, T2 and T3 are piston sections,
and indicate the operating time to move, respectively.

Here, the feature of the present invention is that the control circuit
The gear shift characteristics of the vehicle are stored in the CP in advance, and when the driver operates the lever unit LU to command a gear change, the control circuit CP detects the gear position at that point using the gear position sensor GS. And at the same time check the vehicle speed with speed sensor
The rotational speed of the engine is detected by SS2 and the rotational speed sensor SS1. By comparing these detection inputs with the vehicle's preset speed change characteristics, the time T2 required for the piston to pass through the section is calculated, and during this time T2, the coil (not shown) of the exhaust valve is closed. It's in your control.

That is, the magnitude of the synchromesh load, which is a transient state of gear switching, is calculated from the input value indicating the running state of the vehicle at the time when the gear switching command is received from the driver and the speed change characteristics of the vehicle.
In order to move the piston so that the pressure of the piston does not affect the synchronized mesh load calculated above, the required length of time between T1 and T2 in FIG. 2 is calculated.

Therefore, when the driver issues a command to change gears using the lever unit LU, the following will occur.

FIG. 3a is a diagram in which the engine rotational speed and vehicle speed are determined using the gear position as a parameter based on the speed change characteristics of the vehicle. FIG. 3b shows a diagram for determining the shift state at each gear position when the engine rotational speed is Ni in FIG. 3a. Here, when the engine speed is Ni, if the driver tries to shift gears to third gear, it will be determined that if the vehicle speed is between ob, it will be an upshift, and if the vehicle speed is between bc, it will be a downshift. Ru. If the speed is higher than point c, it will be an overrun region.

In other words, the control circuit CP shown in Figure 1 compares the inputs of each sensor with the vehicle's previously stored shift characteristics, and determines whether to shift up or down in order to move to the position instructed by the driver. Determine whether

FIG. 4a shows a gear change state diagram when shifting down from fourth gear to third gear, and FIG. 4b shows a gear switching state diagram when shifting up from third gear to fourth gear.

When the driver issues a command to shift to third gear using the lever unit LU in FIG. 4a, the control circuit CP confirms that the gear is in fourth gear at that moment.
Next, the meshing of this fourth speed gear is set to neutral, but at this time the rotational speed of the gear decreases over time. In this case, the time T1 required from the start of gear neutral operation to the start of synchronized mesh operation can be determined by experiment, so T
The engine rotation speed Z1 at the end of 1 can be determined by calculation. The value of Z1 is compared with the engine rotational speed W1 when the gear is switched to third gear. The larger this difference ΔR is, the greater the load on the synchromesh mechanism becomes.

Experiments have shown that for a constant value of this difference ΔR, the time required for the piston to be driven without straining the synchro mesh mechanism, that is, the time required to drive the piston without straining the synchro mesh load, is determined. The travel time is determined in advance, and the magnitude of T2 is calculated based on the engine rotational speed ΔR. For example, Figure 4b is a state diagram when shifting up from third gear to fourth gear, but since the value of ΔR in Figure 4b is smaller than ΔR in Figure 4a, Figure 4b synchronized mesh operation time T2
is calculated to be shorter than that in FIG. 4a. In this case, the time T2 in Fig. 4b is shortened, but as mentioned above, it is predetermined in advance to perform the synchro mesh operation easily against the synchro mesh load, so the synchro mesh mechanism is The life of the synchronized mesh mechanism will not be shortened by increasing the load.

In addition, in the examples a and b in Fig. 4, it happens that the time T
1 are the same, but T1 is controlled to vary depending on the vehicle speed.

〔Effect of the invention〕

According to the present invention, by controlling the exhaust circuit of the solenoid valve that drives the piston of the pressure cylinder depending on the magnitude of the synchronizing mesh load, the synchronizing mechanism is prevented from being subjected to an unreasonable burden. This has the effect of extending the life of the mesh mechanism.

[Brief explanation of drawings]

Fig. 1 is a block diagram of the main parts according to an embodiment of the present invention, Fig. 2 is a diagram of the operating state of the pressure cylinder, Fig. 3 is a diagram of shift characteristics with respect to vehicle speed, and a is a characteristic of each gear with respect to engine rotation speed. , b is a shift state determination diagram, FIG. 4 is a switching state diagram, a is a downshift state, and b is a shift up state. C...Pressure cylinder, CP...Control circuit, D...
...Transmission, E...Engine, EV...Exhaust valve, GS
... Gear position sensor, I/O ... Input/output interface, LU ... Lever unit, LV ... Lever, PR ... Piston rod, DS ... Piston,
R...Air tank, SL1, SL2...Solenoid valve,
SM...Speedometer, SS1...Engine rotation speed sensor, SS2...Speed sensor, SU...Shift unit, W1, W2, Z1, Z2...Each operating point.

Claims (1)

[Claims] 1. A pressure cylinder, a piston that moves within the pressure cylinder, and a piston rod connected to the piston, a lever of a transmission being connected to the piston rod, and a lever of a transmission connected to the piston rod. In a transmission control device, the transmission control device includes a valve device that is provided on both sides of a movement range of a pressure cylinder and allows fluid pressure to flow in and out of a pressure cylinder, and a control circuit that includes a microcomputer that controls the valve device. an engine rotational speed detection means for detecting a vehicle speed; and a vehicle speed detection means for detecting a vehicle speed; 1. A control device for a transmission, comprising: a control means for gently controlling the time, and the control means includes means for taking detection outputs of the two detection means and calculating the predetermined time.