JPH0419463A - Continuously variable transmission control device for vehicle - Google Patents

Abstract

PURPOSE:To make setting possible of a minimum car speed, that is, maximum reduction ratio of a continuously variable transmission in accordance with will of a driver by providing a speed change ratio determining means, which can set reduction ratio corresponding to operation of a car speed control device such as an inching pedal or the like, in a continuously variable transmission control device for a vehicle. CONSTITUTION:In a controller 100, reduction ratio rhoa corresponding to an accelerator pedal position is calculated by inputting information from each sensor of positions of an accelerator pedal 23 and an inching pedal 24, engine speed and belt input/output rotational speeds. Here, in the case of the inching pedal 24 stepped in, the calculated reduction ratio rhoa is compared with reduction ratio rhoi, when it is corrected by stepping in the inching pedal in the preceding time routine, and target reduction ratio rhog is obtained by performing arithmetic operation of increasing the reduction ratio in accordance with a step-in amount of the inching pedal when a relation is rhoa<rhoi. Next, outputs to a corresponding drive side pulley pressure proportional valve 21 and driven side pulley pressure proportional valve 22 are calculated and output by calculating a deviation E of present belt reduction ratio rhop from the target reduction ratio rhog.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a continuously variable transmission control device for a vehicle.

[Prior Art] A conventional control device for a continuously variable transmission for a vehicle using a pulley and a V-belt is disclosed in Japanese Patent Publication No. 3-29144. This automatic transmission control device controls the rotational speed of the prime mover,
Based on the detection results of the vehicle's running load and vehicle speed, the target gear ratio is determined from the optimum gear shift characteristics predetermined by the electronic control circuit, and the gear ratio is controlled by a hydraulic control signal corresponding to the target gear ratio. , it is now possible to perform highly accurate continuously variable speed control according to the vehicle's driving conditions.

[Problems to be Solved by the Invention] However, in the automatic transmission control device for a continuously variable transmission as described above, the gear ratio is always automatically determined, so when this is installed in a construction machine, has the following problems. That is, in construction machinery, there are cases where it is desired to drive the working machine at a high speed (therefore, keep the engine rotating at a high speed) and to keep the traveling speed of the vehicle low. For example, when a wheeled trenching machine is used to load earth and sand onto a truck, the truck must be approached at low speed from the excavation site, during which time the packets must be lifted from the ground to dump height. In such cases, with conventional automatic transmission control devices, the gear ratio is automatically determined based on the rotational speed of the prime mover, the running load of the vehicle, and the vehicle speed. The vehicle would approach the truck before it could even rise to the top.

The present invention has focused on the above-mentioned conventional problems, and an object of the present invention is to provide a continuously variable transmission control device for a vehicle that makes it possible to set the minimum vehicle speed, that is, the maximum reduction ratio of the continuously variable transmission according to the driver's intention. .

[Means for Solving the Problems] In order to achieve the above object, a continuously variable transmission control device for a vehicle according to the present invention is connected to a prime mover via a torque converter and a forward/reverse clutch, and is capable of controlling groove spacing. In a belt-type continuously variable transmission having a driving pulley, a driven pulley connected to the driving wheel side and capable of controlling groove spacing, and a belt wrapped around both of the pulleys, A means for determining the minimum reduction ratio of the continuously variable transmission corresponding to the operation amount, a means for determining the belt speed ratio according to the load from the rotation speed of the prime mover and the output rotation speed of the torque converter, and operation of the vehicle speed control device. The configuration includes a speed ratio determining means that can set a maximum reduction ratio based on the following.

[Operations] According to the above configuration, the continuously variable transmission control device for a vehicle includes means for determining the minimum reduction ratio of the continuously variable transmission corresponding to the operation amount of the prime mover acceleration/deceleration device, and the rotational speed of the prime mover and the output rotational speed of the torque converter. A belt gear ratio determining means is provided, which is determined according to the load, and a gear ratio determining means is capable of setting the maximum reduction ratio based on the operation of the vehicle speed control device, so that the driver can easily operate the prime mover acceleration/deceleration device. The belt minimum speed reduction ratio is determined according to the amount, and the belt speed change ratio is automatically corrected according to the input/output rotation speed ratio, that is, the speed ratio of the torque converter. When the driver wishes to further reduce the vehicle speed, by operating the vehicle speed control device, the belt transmission ratio is re-corrected in accordance with the amount of operation.

Therefore, when the vehicle speed side wJ device is not operated, the belt gear ratio is adjusted according to the running load (traction force required for work) by the prime mover rotation speed set based on the operation of the prime mover acceleration/deceleration device and the speed ratio of the torque converter. automatically controlled. In addition, the reduction ratio is corrected according to the amount of operation of the vehicle speed control device, and the vehicle speed can be reduced to the driver's intended speed.
The driver's intentions can now be reflected in vehicle speed control, improving vehicle operability.

[Example 7] Examples of the continuously variable transmission control device for a vehicle according to the present invention will be described in detail below with reference to the drawings.

In FIG. 1, a reverse gear 4 and a hydraulic forward clutch 5 are attached to an output shaft 3 of a torque converter 2 connected to an engine 1, and a reverse main gear 7 is attached to an output shaft 6 of the forward clutch 5. is fixed, and the shaft end is connected to the drive pulley 8. Further, a hydraulic reverse clutch 12 is attached to the shaft 11 of the driven gear 10 that meshes with the reverse gear 4 via the intermediate gear 9, and an output shaft 13 of the reverse clutch 12 meshes with the reverse main gear 7. Reverse secondary gear] 4 is fixed. An endless ■belt 15 from the drive side pulley 8
The driven pulley 16 to which the power is transmitted is arranged on the same axis as the vehicle drive output shaft 17.

As a hydraulic power source for belt control and hydraulic forward/reverse clutch control, a hydraulic pump 18 is connected to the output shaft of the engine 1 via a gear (not shown), and the piping of the hydraulic pump 18 is connected to a pressure proportional valve 19.20.21. 22 to the forward clutch 5, reverse clutch 12, driving pulley 8, and driven pulley 16. Note that the pressure proportional valves are electrohydraulic proportional valves, and wiring for manually inputting control signals to these valves is provided between them and the controller 100. In addition, the engine speed sensor 10 is mounted on the engine 1 output shaft.
1. Belt manual rotation speed sensor 102 on the output shaft 6, belt output rotation speed sensor 103 on the output shaft 17, accelerator pedal position sensor 104 on the accelerator pedal 23, and inching pedal position sensor 105 on the inching pedal 24 provided as a vehicle speed control device. A shift lever switch 106 is attached to each of the shift levers 25 and 25, and wiring for manually transmitting electrical signals from these sensors and switches to the controller 100 is provided between the controller 100 and the shift lever switch 106. Furthermore, a circuit 27 for supplying hydraulic oil to the torque converter 2 via the relief valve 26 is connected to the torque converter 2 and in turn to a transmission lubrication circuit 28 .

FIG. 2 is a diagram showing the process of continuously variable transmission according to the present invention.
The belt gear ratio is adjusted depending on whether or not the ink pedal is depressed.

Controller 100 for belt speed ratio control and clutch control
is shown in Figure 3. As shown in the figure, a controller 100
Electric signals from an engine rotational speed sensor 101, a belt manual rotational speed sensor 102, a belt output rotational speed sensor 103, an accelerator pedal position sensor 104, an inching pedal position sensor 105, and a shift lever switch 106 are respectively input to the .

Signals from these sensors are sent to the human interface 11
Sent to 1. Although not shown here, the waveform shaping circuit A
/D converter is inserted as necessary. controller 1
00 is human interface 111, CPtJ 112
, ROM 113, RAM 114, and output interface 115, which are connected by an address bus and a data bus. In ROM113,
It stores programs for performing belt speed ratio control and clutch control, and data necessary for the control. R.A.
Information from the various sensors and switches, parameters necessary for control, etc. are temporarily stored in M114. The output signals of the controller 100 are output to amplifiers 116 and 1, respectively.
17, 118, 119 through pressure proportional valves 19, 20,
Output on 21.22.

Next, specific details of the belt speed ratio control performed by the controller 100 will be described. The belt speed ratio control routine 200 is shown in FIG.

First, in step 201, information from each sensor of the accelerator pedal position, engine rotation speed, belt output rotation speed, and inching pedal position is read. Then step 2
02, a reduction ratio ρa corresponding to the accelerator pedal position is calculated. For example, as shown in Fig. 5, when the accelerator pedal stroke is Xa, ρa = f(xa
) It may be calculated using a function expressed as , or it may be searched from table data. In addition, in Fig. 5, ρma
x is the maximum reduction ratio that the belt-type continuously variable transmission can take mechanically, and ρmin is also the minimum reduction ratio.

In this step, the minimum reduction ratio that can be calculated from the accelerator pedal position is set. Further, if the inching pedal is depressed, the routine proceeds to step 204 and subsequent steps, and if the inching pedal is not depressed, the routine proceeds to step 220, which will be described later.

If the inching pedal is depressed, step 2
The reduction ratio ρa calculated in step 02 is compared with the reduction ratio ρ1 when the inching pedal was depressed and the reduction ratio was corrected in the previous routine, and if ρa - ρ1, the process goes to step 205; otherwise, the process goes to step 205. is step 207 ρ
After replacing a with ρ1, the process proceeds to step 205. In this step, if ρ1 was reset in the previous routine, ρ1=0, so step 207
to set the reduction ratio at the start of inching. Next, in step 205, a calculation is performed to increase the reduction ratio according to the amount of depression of the inching pedal, and the result is set as the target reduction ratio ρg. In other words, this is an operation to reduce the vehicle speed. Here, for example, as shown in Figure 6, when the previous reduction ratio is ρ1 and the inching pedal stroke is xl, ρg=j(ρ
It is calculated using the function expressed as xi).

On the other hand, if the ink pedal is not depressed, the speed ratio e of the torque converter is calculated using the following equation (0) in step 220. Note that in equation 0, kl is a constant.

Next, in step 221, the corrected reduction gear ratio ρi corresponding to e is determined. Here, for example, as shown in Figure 7, ρg,
It may be calculated as a function expressed as =J(ρa, e). Further, in step 222, the corrected reduction ratio ρi is replaced with the target reduction ratio ρg to facilitate processing.

Next, in step 208, the current reduction ratio ρp is calculated using the following equation 0, and in step 209, the deviation E between the target reduction ratio ρg and the current belt reduction ratio ρp is calculated.

Next, in step 210, the output to the drive-side pulley pressure proportional valve 21 and the output to the driven-side pulley pressure proportional valve 22 corresponding to the deviation E are calculated, and the values are output to the respective pressure proportional valves. Return.

This type of control makes it possible to reduce the vehicle speed as intended when the driver depresses the inching pedal, and if the driver does not depress the inching pedal, the deceleration ratio is automatically adjusted according to the driving load. Set.

[Effects of the Invention] As explained above, the present invention is characterized by providing a continuously variable transmission control device for a vehicle with a speed ratio determining means capable of setting a reduction ratio corresponding to the operation of a vehicle speed control device such as an inching pedal. Therefore, when the vehicle speed control device is not operated, the belt speed ratio is automatically controlled according to the driving load (traction force required for work) by the speed ratio of the accelerator pedal and the torque converter. In addition, by operating the vehicle speed control device,
The gear ratio is corrected and the vehicle speed can be reduced to the speed intended by the driver. Therefore, the vehicle speed control when traveling while working can reflect the driver's intention, and the operability of various vehicle-based construction machines, industrial vehicles, etc. can be improved.

[Brief explanation of the drawing]

FIG. 1 is a hydraulic and electrical circuit diagram showing a schematic configuration of a continuously variable transmission system 1aII for a vehicle according to an embodiment, FIG. 2 is a diagram showing a process of continuously variable transmission according to the present invention, and FIG. 3 is a diagram showing a continuously variable transmission process according to the present invention. FIG. 4 is a diagram showing the internal configuration of the controller, FIG. 4 is a diagram showing the control routine of the controller, FIG. 5 is a diagram showing the relationship between the accelerator pedal stroke and the minimum reduction ratio, and FIG. FIG. 7 is a diagram showing the relationship between the speed ratio of the torque converter and the target reduction ratio. 1... Engine 2... Torque converter 5... Forward clutch 8... Drive side pulley 12... Reverse clutch 15. ... V-belt 16 ... Driven pulley 18 ... Hydraulic pump 23 ... Accelerator pedal 24 ... Inching pedal 100 ... Controller patent applicant: Komatsu Ltd. Figure 3 Figure 4 Accelerator pedal stroke (Xa) Inching pedal stroke (Xi)

Claims (1)

[Claims] A driving pulley is connected to the prime mover via a torque converter and a forward/reverse clutch and is capable of controlling groove spacing; a driven pulley is connected to the driving wheel side and capable of controlling groove spacing; In a belt-type continuously variable transmission having a V-belt, a means for determining a minimum reduction ratio of the continuously variable transmission corresponds to an operation amount of a prime mover acceleration/deceleration device, and a rotation speed of the prime mover and an output rotation speed of a torque converter. A continuously variable transmission for a vehicle, characterized in that it has a belt speed ratio determining means that is determined according to the load, and a speed ratio determining means that is capable of setting a maximum reduction ratio based on the operation of a vehicle speed control device. Control device.