JPH0452538A - Torque detecting apparatus of automatic transmission - Google Patents

Abstract

PURPOSE:To improve the assembling accuracy, assembling easiness, reliability and detecting accuracy of a detecting means by providing a pair of detecting heads for a fixed sleeve which is loosely outfitted to a turbine shaft and fixed to a stator fixed shaft. CONSTITUTION:In this apparatus, a magnetic pattern can be written into parts 45a, 45b to be detected at any time when driving is started or during driving of the apparatus, and the axial torque of a shaft 3 can be operated wit good accuracy without being adversely influenced by the torsion remaining in a turbine shaft 3 or the positional displacement of magnetic heads 46, 47. The heads 46, 47 and a sealed bearing 44 can be integrally assembled with a fixed sleeve 40 and the fixed sleeve 40 can be assembled with an automatic speed change gear 1. Accordingly, the assembling accuracy and assembling easiness can be improved. The space between heads 46, 47 and parts 45a, 45b to be detected can be generally uniformly maintained by the bearing 44, and at the same time, lubricating oil or the like is prevented from entering the space. Since the sleeve 40 is extended to the side of a turbine hub 16, the space between the heads 46 and 47 is enlarged and the detecting accuracy of the axial torque can be improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a torque detection device for an automatic transmission, and in particular to one that detects shaft torque from the rotational phase difference between two parts of a turbine shaft that are spaced apart in the axial direction. Regarding.

[Prior art]

Normally, automatic transmissions in automobiles control line pressure settings based on throttle valve opening, etc.
Recently, a system has been proposed in which the shaft torque of the turbine shaft is directly detected by a torque detection device, and this detected data is used to control line pressure and the like with higher precision.

As a torque detection device for the above-mentioned automatic transmission, for example, Japanese Patent Application Laid-Open No. 64-21255 discloses a method in which detected portions having shape magnetic anisotropy are formed in two portions spaced apart in the axial direction on the outer circumference of a turbine shaft. , a system is described in which detection sensors for detecting the detected parts formed in these two parts are fixed to the stator shaft, and the axial torque of the turbine shaft is detected based on the output from the rain detection sensor. ing.

On the other hand, conventionally known torque detection devices detect shaft torque of a power transmission shaft rotationally driven by an engine, an electric motor, etc., which detect shaft torque from the torsional angle of the power transmission shaft. .

Usually, in the above torque detection device, detected parts are formed at two parts separated in the axial direction of the power transmission shaft, and a pair of sensors for detecting these detected parts are mounted on a fixed member outside the power transmission shaft. It is arranged to face the detected part, and is configured to determine the rotational phase difference between two separated parts based on the outputs of both sensors, and calculate the torsion angle of the power transmission shaft from the rotational phase difference to determine the shaft torque. There is.

[Problems to be Solved by the Invention] In the above-mentioned publication and the conventional torque detection device, since a phase error in assembling a pair of sensors causes an error in the detected torque,
It is necessary to assemble a pair of sensors with high precision, but it is extremely difficult to assemble a pair of sensors with high precision to separate parts of a fixed member so as to correspond to a pair of separated detected parts. However, in the case of automatic transmissions, there are fixed members only in a very limited area on the outer periphery of the turbine shaft, so it is not possible to set a large axial distance between the pair of sensors, and the shaft torque It is difficult to improve the detection accuracy of
There are problems such as.

Furthermore, the torque detection device disclosed in the above publication is not provided with a sealing member that seals the gap between the detection sensor and the turbine shaft. If the gap between the detection sensor and the turbine shaft becomes uneven due to assembly errors, there is a problem in that it becomes difficult to obtain a stable sensor output.

SUMMARY OF THE INVENTION An object of the present invention is to provide a torque detection device that can improve the assembly accuracy, ease of assembly, and reliability of a detection means, and can relatively easily improve the detection accuracy of shaft torque.

[Means to solve the problem]

A torque detection device for an automatic transmission according to a first aspect of the present invention is a torque detection device for an automatic transmission that detects shaft torque from a rotational phase difference between two parts spaced apart in the axial direction of a turbine shaft. A fixed sleeve is attached to the fixed sleeve and fixed to the stator fixed shaft, a sealed bearing is attached to an annular gap between the fixed sleeve and the turbine shaft at both ends of the fixed sleeve, and a turbine is connected between the pair of sealed bearings. A pair of detected parts provided on the outer circumferential surface of two parts separated in the axial direction of the shaft, and a pair of detection heads provided in parts of the fixed sleeve corresponding to the pair of detected parts. It is prepared.

The torque detection device for an automatic transmission according to the second claim comprises a first
In the torque detection device for an automatic transmission according to the present invention, one end portion of the fixed sleeve extends from the stator fixed shaft toward a turbine hub connected to a shaft end of the turbine shaft.

[Effect]

In the torque detection device for an automatic transmission according to the first aspect, the fixed sleeve is attached to the turbine shaft in a loosely fitted manner and is fixed to the stator fixed shaft, and the outer periphery of two parts spaced apart in the axial direction of the turbine shaft. A pair of detected parts provided on the surface are respectively detected by a pair of detection heads provided on the fixed sleeve, and the shaft torque of the turbine shaft is detected from the rotational phase difference of the turbine shaft in the dual wave detection parts. . Sealed bearings are installed in the annular gap between the fixed sleeve and the turbine shaft at both ends of the fixed sleeve, and this pair of sealed bearings prevents lubricating oil from entering between the detection head and the detected part. Since the gap between the detection head and the detected part is maintained uniformly, stable shaft torque detection is possible, and reliability of the torque detection device can be improved. With a pair of detection heads and a pair of sealed bearings assembled to the fixed sleeve, these can be assembled into an automatic transmission, greatly improving the assembly accuracy and ease of assembly of the detection heads and sealed bearings. can be improved.

In the torque detection device for an automatic transmission according to the second aspect, the same effect as in the first aspect can be obtained.

In addition, since one end of the fixed sleeve extends from the stator fixed shaft to the turbine hub connected to the shaft end of the turbine shaft, the distance between both detection heads can be reduced without changing the configuration of the automatic transmission. By increasing the size, the accuracy of detecting the shaft torque of the turbine shaft can be easily improved.

〔Effect of the invention〕

According to the torque detection device for an automatic transmission according to the first aspect, as detailed in the [Operation] section above, it is possible to detect stable shaft torque and improve the reliability of the torque detection device. , the assembly accuracy and ease of assembly of the detection head and the sealed bearing can be significantly improved.

According to the torque detection device for an automatic transmission according to the second aspect, the same effects as in the first aspect can be obtained.

In addition, the accuracy of shaft torque detection can be easily improved by increasing the distance between the two detection heads without changing the configuration of the automatic transmission.

〔Example〕

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

This embodiment is a case where the present invention is applied to a torque detection device that detects the shaft torque of a turbine shaft of an automatic transmission for an automobile.

First, to briefly explain the automatic transmission 1, as shown in FIG. 1, a turbine shaft 3 is provided coaxially with a crankshaft 2 of an engine (not shown), and a torque converter 4 and an oil pump are connected to the turbine shaft 3. 5 and a multi-stage transmission mechanism 6 are arranged coaxially in order from the engine side, and a hydraulic control valve unit 7 for controlling the speed change of the multi-stage transmission mechanism 6 is provided below the multi-stage transmission mechanism 6.

The torque converter 4 includes a pump 10, a turbine 11, and a stator 12, as shown in FIG. The turbine 11 is connected to the turbine shaft 3 via the turbine hub 16, and the stator 1 is connected to the drive gear 15 of the oil pump 5 through the
2 is connected to the stator fixed shaft portion 22 of the oil pump 5 via a one-way clutch 17, and the rotational force of the crankshaft 2 is transferred from the pump IO to the turbine 11 via the oil circulating between the pump 10 and the turbine 11. and is transmitted to the turbine shaft 3 via the turbine hub 16.

The oil pump 5 is assembled into a pump housing 20 and a pump cover 21 that are fixed to the casing 8 of the automatic transmission 1, and the pump cover 21 has a substantially cylindrical stator that extends toward the engine and is connected to the one-way clutch 17. A fixed shaft portion 22 and a substantially cylindrical fixed shaft portion 23 extending toward the multi-stage transmission mechanism 6 are formed, and the turbine shaft 3 is rotatably inserted into the re-fixed shaft portions 22 and 23.

The hydraulic control valve unit 7 includes a control valve mechanism that switches and controls the multi-stage transmission mechanism 6, etc., and a line pressure setting mechanism that sets the line pressure (hydraulic oil pressure) in the automatic transmission 1. Unit 7 is controlled by control unit 30.

The control unit 30 includes a microcomputer storing a control program for executing speed change control with predetermined characteristics, and includes an engine throttle opening sensor 3.
1, an idle switch 32, a vehicle speed sensor 33, a plurality of switches 34 for detecting the setting states of the operating levers on the driver's seat, and various signals from a torque detection device (described later), etc., are supplied to the control unit 30, and based on these signals, the The control unit 30 controls the control valve mechanism and the line pressure setting mechanism, and automatically changes gears and sets the line pressure depending on the driving condition of the vehicle. The hydraulic control valve unit 7 is a well-known type, and the gear shift and line pressure setting are performed by automatic gear shift control.

The torque detection device is for detecting the shaft torque of the turbine shaft 3 used in line pressure setting control, and is shown in Fig. 2.
As shown in FIG. 3, a substantially cylindrical fixing sleeve 40 is attached to the turbine shaft 3 corresponding to the front half of the stator fixed shaft portion 22.
is loosely fitted, and the fixed sleeve 40 is attached to the stator fixed shaft portion 2.
2 and is fixed to the stator fixed shaft part 22 via a screw member 41, and the distal end of the fixed sleeve 40 extends toward the turbine hub 16 side and is absorbed into the rear part of the turbine hub 16, and the fixed sleeve 40 An annular groove 42 is formed in the inner periphery of both ends of the turbine, and a sealed bearing 44 is installed in an annular gap 43 between each annular groove 42 and the turbine shaft 3.
The pair of hair rings 44 with seals allow the fixed sleeve 40 to rotate freely relative to the turbine shaft 3 with a predetermined gap, and the fixed sleeve 40 and the turbine shaft 3
This prevents lubricating oil from entering the gap between the two.

A substantially cylindrical magnetic recording layer 45 is formed on the outer periphery of the turbine shaft 3 between the two sealed bearings 44 by thermal spraying.
The magnetic recording layer 45 is formed up to the vicinity of the bearings 44 with both seals, and a pair of magnetic heads 46 and 47 are mounted on the upper part of the fixed sleeve 40, facing the detected parts 45a and 45b at both ends of the magnetic recording layer 45. , the magnetic heads 46 and 47 are connected to the control unit 30 of the automatic transmission 1, respectively. Incidentally, the magnetic heads 46 and 47 are connected to the detected parts 45a and 4 by electric signals from the control unit 30.
A predetermined magnetic pattern can be written on the detection target portions 45a and 45b, and an electric signal corresponding to the magnetic pattern written on the detected portions 45a and 45b can be output to the control unit 30. The reference numeral 48 is a connector for connecting the lead wires 49 of the magnetic heads 45a and 45b and the lead wire 50 from the control unit 30, and the reference numeral 51 is a passage for guiding the lead wire 50 to the outside of the pump cover 21. It is.

The above torque detection control will be briefly explained.

A control program for torque detection control is input and stored in advance in the microcomputer of the control unit 30, and for example, when starting operation, the idle switch 3
2 and the neutral switch of switch 34 is O.
When in the N state, that is, during idle operation and no load is acting on the turbine shaft 3, a digital signal of a predetermined frequency is output from the control unit 30 to the magnetic heads 46 and 47, as shown in FIG. Detected part 4
Magnetic patterns corresponding to digital signals having the same frequency and the same phase are written in 5a and 45b.

Next, after writing to the detected parts 45a and 45b is completed, the magnetic patterns stored in the detected parts 45a and 45b are read by the magnetic heads 46 and 47 at any time, and the positions of the digital signals output from the magnetic heads 46 and 47 are read. Detected part 45a from phase difference
- The torsion angle of the turbine shaft 3 between 45b is calculated, and the axial torque of the turbine shaft 3 is determined from the torsion angle and output to the line pressure setting control.

The calculation of the shaft torque will be explained with reference to FIGS. 4 and 5.

Rotation speed N0 of the turbine shaft 3 when the torque load is released
, the write frequency fO of the magnetic heads 46 and 47 (see FIG. 4), and the number of magnetic point sequences stored in the detected parts 45a and 45b as Z, the relationship of equation (1) holds true.

r o = z No HHHm Next, when torque is applied to the turbine shaft 3, the turbine shaft 3 is twisted, and as shown in FIG. Part 45
A phase difference Δt corresponding to the torsion angle θ of the turbine shaft 3 between a and 45b occurs.

Here, the rotation speed of the turbine shaft 3 is N, and the magnetic head 46 is
As the frequency f of the digital signal obtained from 47, the relationship of equation (2) holds true between the twist angle θ and the phase difference Δt.

θ=2πNΔt =2π(f/Z)Δt=2π(N(+/fo) fΔt...(2)
However, as in (1) 2, the relationship f=NZ was used.

On the other hand, assuming that the torque loaded on the turbine shaft 3 is T, the relationship between the torque T and the torsion angle θ is as shown in equation (3).

T=πCd' θ/32L (3) where G is the transverse elastic modulus of the turbine shaft 3, d is the diameter of the turbine shaft 3 between the detected parts 45a and 45b, and L is the diameter between the detected parts 45a and 45b. is the distance.

Next, by substituting equation (2) into equation (3), equation (4) can be obtained. This equation represents the relationship between the torque T and various variables for writing and reading magnetic patterns.

T=π2 Gd4 (No /f0)fΔt/16L
・ ・ ・(4) Next, the operation of the torque detection device will be explained.

In systems such as automatic transmissions 1 of automobiles, where a wide range of torque is applied intermittently over a long period of time, fatigue accumulates on the turbine shaft 3, resulting in residual torsion even in no-load conditions, or distortion during driving. Due to vibrations, the mounting positions of the magnetic heads 46 and 47 will shift due to aging.

In the above-mentioned torque detection device, a new magnetic pattern can be written in the detected parts 45a and 45b at the start of operation of the automobile or at any time during operation, so that the twist remaining in the turbine shaft 3 and the positional deviation of the magnetic heads 46 and 47 can be detected. The shaft torque of the turbine shaft 3 can be calculated with high accuracy without being influenced by

With the magnetic heads 46 and 47 and the sealed bearing 44 integrally assembled to the fixed sleeve 40, the fixed sleeve 40 can be assembled to the automatic transmission 1, and the magnetic heads 46 and 47 and the sealed bearing 44 can be assembled into the automatic transmission 1. Assembly accuracy/
Improves ease of assembly.

The magnetic heads 46 and 47 are mounted by the sealed bearing 44.
The gaps between the magnetic heads 46, 47 and the detected parts 45a and 45b are maintained approximately evenly, and the gaps between the magnetic heads 46 and 47 and the detected parts 45a and 45b are
Since lubricating oil etc. is prevented from entering between 45b,
The reliability of the torque detection device is greatly improved.

By extending the fixed sleeve 40 toward the turbine hub 16, the distance between the two magnetic heads 46 and 47 is increased, so that the detection accuracy of shaft torque can be improved without changing the configuration of the automatic transmission 1.

As described above, it is possible to improve the assembly accuracy and ease of assembly of the magnetic heads 46 and 47 and the sealed bearing 44, to improve the reliability of the torque detection device, and to almost change the configuration of the automatic transmission mechanism. Effects such as being able to improve shaft torque detection accuracy without any problems can be obtained.

Incidentally, in this embodiment, the magnetic recording layer 45 and the magnetic heads 46 and 4 are
7, the present invention is applied to a torque detection device equipped with The detected portions 45a and 4 are provided with this pair of sensors.
5b may be detected.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a side view of an automatic transmission, FIG. 2 is a vertical sectional view of main parts of the automatic transmission, and FIG.
FIG. 4 is a longitudinal sectional view of the torque detection device, FIG. 4 is an explanatory diagram of digital signals written in the magnetic recording layer, and FIG. 5 is an explanatory diagram of digital signals read from the magnetic recording layer. 1... Automatic transmission, 3... Turbine shaft, I6... Turbine hub, 21... Pump cover 22... Stator fixed shaft portion, 40... Fixed sleeve, 42... Annular groove, 44... Bearing with seal , 45a・45b・
・Detected part, 46・47・ ・Magnetic head.

Claims (2)

[Claims] (1) In a torque detection device for an automatic transmission that detects shaft torque from the rotational phase difference between two parts separated in the axial direction of the turbine shaft, a fixed part is attached to the turbine shaft in a loose fit and fixed to the stator fixed shaft. a sleeve, a sealed bearing installed in an annular gap between the fixed sleeve and the turbine shaft at both ends of the fixed sleeve, and an outer periphery of two parts spaced apart in the axial direction of the turbine shaft between the pair of sealed bearings. Torque of an automatic transmission characterized by comprising: a pair of detected parts provided on a surface; and a pair of detection heads provided at parts of a fixed sleeve corresponding to the pair of detected parts. Detection device. (2) The torque detection device for an automatic transmission according to claim 1, wherein one end of the fixed sleeve extends from the stator fixed shaft toward the turbine hub connected to the shaft end of the turbine shaft. .