JPS63312551A - Torque detection device for automatic transmission - Google Patents

Abstract

PURPOSE:To correctly detect shock caused by shifting by forming a torque detection face of shape-magnetic-anisotropy on the rear side of the final stage fastening element of an output shaft, and providing a torque detection device on a cylindrical member on the transmission side opposing thereto. CONSTITUTION:In the rear side of the final stage fastening element of an automatic transmission, on the outer peripheral face of an output shaft 17, first and second group lines 32A, 32B which have shape-magnetic-anisotropy, are deformed in their shapes by tension and have increased magnet transmission rate namely have positive magnetic distortion characteristic. To a cylindrical member 20 on a transmission case side opposed to the lines 32A, 32B, a torque detector 30B having a detection coil is fitted. When the first and second group lines 32A, 32B of a torque detection face 30A receive tension or compression caused by fluctuation of torque of the output shaft 17, the rate changes and then it is detected by the torque detector 30B. It is thus possible to detect torque fluctuation of shifting shock and the like, in a non-contact condition and good responsiveness and to enable desirable shift control.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a torque detection device that detects rotational torque transmitted to the output shaft of an automatic modification machine used in a vehicle, and in particular, relates to a torque detection device that detects rotational torque transmitted to the output shaft of an automatic modification machine used in a vehicle. It is designed to detect

[Conventional technology]

Conventional torque detection devices for automatic modification machines include, for example, Japanese Patent Laid-Open No. 61-12795.2 and Japanese Patent Laid-Open No. 61-12.
Some of them are described in Japanese Patent No. 7953.

In this conventional example, one or more torque detectors each having a built-in torque detection element are attached to the rear end of a transmission case of a vehicle, a fitting structure, a rib and a screw structure that engages with the rib, and a screw structure that engages with the fitting structure.
Alternatively, the torque detector is attached using a flange structure, and the detection surface of the torque detector is opposed to the output shaft extending from the transmission case at a predetermined distance in the circumferential direction.

The torque detector has a configuration in which an excitation coil and a detection coil are wrapped around a substantially U-shaped magnetic core, and the outer peripheral surface of the output shaft facing the torque detector is designed to increase detection sensitivity. A thin film (ribbon) with a thickness of 20 to 30 μm made of an i31 material such as amorphous is adhered to the substrate with a heat-resistant adhesive.

[Problem that the invention seeks to solve]

However, in the above-mentioned conventional torque detection device for automatic modification machines, a torque detection head in which an excitation coil and a detection coil are wound around a magnetic core is used as the torque detector, so the mounting position thereof is in the transmission. It is limited to the rear extension that is connected to the outside and cannot be installed inside the transmission case.There is no problem if there is a rear extension, but if there is a sub-transmission or 4-wheel drive at the rear of the automatic transformation machine. When the transfers are directly connected, there is a problem in that a torque detector cannot be provided. In addition, in order to detect torque fluctuations due to shift shock that occurs when shifting by applying hydraulic pressure to each fastening element, it is necessary to locate the final stage of the fastening element of the output shaft, that is, near the rotational force transmission part to the output shaft. The most accurate torque detection can be performed by detecting the torque at There was also the problem that it could not be done.

Therefore, this invention has been made by focusing on the problems of the above-mentioned conventional example, and is an automatic modification system that can solve the problems of the above-mentioned conventional example by detecting the torque of the output shaft inside the transmission case. The purpose of this invention is to provide a torque detection device for a machine.

[Means for solving problems]

In order to achieve the above object, the present invention provides an automatic transmission system in which driving force from an engine is transmitted through an input shaft, and the driving force is automatically shifted and transmitted to an output shaft by appropriately selecting a plurality of fastening elements. In the modification machine, a torque detection surface having shape magnetic anisotropy is formed on the outer circumferential surface of the output shaft within the transmission case and on the side subsequent to the final stage of the fastening element, and the transmission case side facing the torque detection surface. It is characterized in that a torque detector having a flat detection coil is attached to a cylindrical member.

[Effect]

In this invention, a torque detection surface is formed by directly imparting shape magnetic anisotropy to the circumferential surface of the output shaft, or by pasting a thin film having shape magnetic anisotropy, and By arranging a torque detector that includes a flat detection coil, the magnetic permeability of the torque detection surface changes due to the tensile or compressive force caused by the torque acting on the torque detection surface, and the magnetic permeability changes. Changes are detected by a detection coil. In this way, since it is only necessary to provide a detection coil as a torque detector, it is possible to arrange the torque detector in a small gap between the output shaft and the transmission-side cylindrical member facing the output shaft in the transmission case. This makes it possible to accurately detect torque fluctuations such as gear change shocks transmitted to the output shaft.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a sectional view of an automatic modification machine showing an embodiment of the present invention.

In the figure, l is a transmission case, and a torque converter housing 2 is integrally connected to the front end side of the transmission case, and a rear extension 3 is connected to the rear end side thereof.

An oil pump housing 4 and an oil pump cover 5 are disposed between the transmission case 1 and the torque converter housing 2, and an input shaft 6 is inserted into the transmission case l through the cylindrical portion of the oil pump cover 5. There is.

A turbine 7t of a torque converter 7 is spline-coupled to a position within the torque converter housing 2 of the input shaft 6, and a sun gear 8a of a planetary gear 8 is fixed to a rear end portion within the transmission case l.

As schematically shown in FIG. 4, a planet carrier 8c of the rear planetary gear 8 is connected to an internal gear 9d of the front planetary gear 9.

On the other hand, a high-speed clutch 10 is inserted between the input shaft 6 and the planet carrier 9c of the front planetary gear 9, and a reverse clutch 11 is inserted between the input shaft and the sun gear 9a of the front planetary gear 9. .

Also, internal gear 8d of rear planetary gear 8
and front planetary gear 9 planet carrier 9
A forward one-way clutch 12, a forward clutch 13, and an overrun clutch 14 are inserted in parallel between the forward planetary gear 9 and the fixed part, and a low-and-reverse brake 15 and a row one-way clutch are inserted between the planet carrier 9C of the forward planetary gear 9 and the fixed part. A clutch 16 is connected in parallel.

On the other hand, planet carrier 8 of rear planetary gear 8
An output shaft 17 disposed coaxially with the input shaft 6 is spline-connected to C, and the output shaft 17 is connected to a propeller shaft (not shown) through the rear extension 3.

The output shaft 17 is rotatably supported by a newdle bearing 18 inserted between the end plate portion 1a of the transmission case 1, and the end plate portion 1a is provided with a shaft facing the output shaft 17 within the transmission case 2. A cylindrical member 20 is fixed thereto.

A torque detection device 30 for detecting rotational torque transmitted to the output shaft 17 is disposed between the output shaft 17 and the cylindrical member 20.

That is, as shown in FIGS. 2 and 3, the torque detection device 30 is configured with a torque detection surface 30A formed on the outer peripheral surface of the output shaft 17 and a coil facing the torque detection surface 30A. 30B, and a measuring section 30G that measures rotational torque based on the detection signal of the torque detector 30B.

The torque detection surface 30A is formed on the outer circumferential surface of a small diameter portion 31 formed at a position close to the front end spline-coupled with the planet carrier 8C of the rear planetary gear 8 to which rotational torque is transmitted to the output shaft 17 in the transmission case 1. and a plurality of groups a along the outer peripheral surface,
..., a first group column 32A (2.6th
(see figure) and a second group column 32B (see figure 2.6) consisting of a plurality of groups b, . . . , b.

Moreover, each of groups a, . . . , a is 1. Output shaft 17
An inclination angle of +45 degrees with respect to the axial direction (see arrow A in Figure 2). ), and on the other hand, each of groups b, .
) are formed at equal intervals.

By the way, groups a, ..., a and su, ..., b
By providing 1. second group column 32A,
32B includes groups a,..., between a and...
. . , b are line-shaped protrusions a I, . . . a / and b' as part of the peripheral surface of the small diameter portion 31.

..., b' is formed (see Fig. 6), and this convex strip a
', ..., a' and b', ..., b' are the angles of inclination of the magnetic flux φ for torque detection, which will be described later, at a predetermined angle (45 degrees in this example) with respect to the shaft axis direction. (see the dotted line in FIG. 6), thereby guiding the first. The second group rows 32A and 32B can have mutually different shape magnetic anisotropies.

For this reason, groups a,..., a and s,..., b
The group length, group width, and group interval for each are set to predetermined values that can ensure the above-mentioned shape magnetic anisotropy.

Actually, the group rows 32A, 32 of the torque detection surface 30A
B is formed by cutting using a cutting machine such as a hobbing machine when forming the output shaft 17.

Here, the first example in this embodiment. Second group column 32
A and 32B are set to have so-called positive magnetostrictive characteristics, in which the magnetic permeability increases when subjected to tensile deformation.

On the other hand, the torque detector 30B is connected to each group column 32A, 3
2B for excitation and detection, which is closely opposed to 2B with a gap of a predetermined distance therebetween. Second coil 33A.

33B, and first and second yokes 34A and 34B which are fixedly disposed on the inner circumferential surface of the cylindrical member 20 and hold the coils 33A and 33B wound therein.

On the other hand, the aforementioned measuring section 30C is configured as shown in FIG. To explain this in detail, in the same figure, '40
is the first. Second coils 33A, 33B and resistance (resistance value R
,,This is a bridge circuit with Ri 41A and 41B. In this bridge circuit 40, the inductance L1 of the first coil 33A is a value including the inductive inductance of the first group column 32A, and similarly, the inductance L1 of the first coil 33A is a value including the inductive inductance of the first group column 32A.
The inductance is a value including the inductive inductance of the second group column 32B. An AC power source 42 is connected to input terminals a and b of this bridge circuit 40, while output terminals c and d are connected to a signal processing section 43 that processes a detection signal.

Here, the frequency of the AC power supply 42 is the group column 32A,
The magnetic flux passing through the 32B is distributed only on its surface, which is a sufficient value (for example, 10kHz) to cause the so-called skin effect.
~30kHz2).

Further, the signal processing section 43 outputs the output terminal c of the bridge circuit 40.
, a rectifier circuit 44A that converts the detection signals from d into direct current,
44B, and a differential amplifier 45 that takes the output of the rectifier circuit 44A as a positive signal and the output of the rectifier circuit 44B as a negative signal, amplifies the difference between them, and outputs the amplified signal as a torque detection signal. There is.

Here, in this embodiment, the inductances L+ and Lx of the bridge circuit 40 are set to be L,=L2 in a state where no rotational torque is transmitted to the output shaft 17. Therefore, in this state, the inductances L+ and Lx of the bridge circuit 40 are The resistance values R, , R2 of the resistors 41A and 41B are set so that the output of the circuit 40 is zero, that is, in a balanced state.

Next, the operation of the above embodiment will be explained.

First, when the select lever (not shown) is set to the neutral range or parking range, both the forward clutch 13 and the reverse clutch 11 are controlled to be in the open state, and the rotational force from the engine input to the input shaft 6 is The rotational torque of the output is not transmitted to the output shaft 17 and remains zero. In this case, the AC power supply 42 of the measurement unit 40B is turned on, and the first and second coils 33A and 33
When an alternating current of a predetermined frequency is supplied to B, a magnetic closed circuit as shown by the dotted line in FIG. 7 is formed.

That is, if we look at this with respect to the magnetic circuit connected to the first coil 33A, each magnetic flux φ passes through the first yoke 34A, the air gap, the first group row 32A, and then becomes a path via the air gap and the first yoke 34A. , which is the second coil 33
The same applies to the magnetic circuit B.

At this time, the first. The magnetic flux φ, .
The surface portions of the second group rows 32A, 32B, that is,
Line-shaped protrusions a/, ..., a' and b', between groups a, ..., a and between groups a, ..., b, ...
. . , pass along b' and at an inclination angle of positive or negative 45 degrees with respect to the axial direction (see the dotted line in FIG. 6). In this state, as described above, since the inductance Ll=L2, the AC outputs of the output terminals c and d of the brifuji circuit 40 are in the same phase and have the same potential. Therefore, the DC outputs of the rectifier circuits 44A and 44B are equal,
The output value of the differential amplifier 45 becomes zero, which represents the rotational torque relative to the output shaft 17.

When the drive range or 2 range is selected with the select lever in order to start the vehicle from this state, the forward clutch 13 and overrun clutch 14 are engaged accordingly, and the forward one-way clutch 12 and the row one-way clutch 16 are engaged. The rotational force from the engine transmitted to the input shaft 6 is transmitted to the output shaft 1 via the sun gear 8a, pinion gear 8b, and planet carrier 8C of the rear planetary gear 8.
7, and the output shaft 17 starts rotating forward.

As a result, the first group column 32A is
The second group row 32B is subjected to compressive deformation in the direction indicated by (2), while the second group row 32B is subjected to tensile deformation in the direction indicated by (2)-(2) in the figure. Due to this deformation action, the magnetic permeability decreases in the first group row 32A, and the magnetic flux φ,...
φ decreases, and eventually the inductance decreases. On the other hand, in the second ° group row 32B, the magnetic permeability increases, and the magnetic flux φ, ..., φ passing therein increases,
As a result, the inductance L2 increases.

Therefore, in the bridge circuit 40 of the measuring section 30C, the balance is lost, and the voltage of the output on the output terminal c-b side becomes higher than the output on the output terminal d-b side. Therefore, in the signal processing section 43, the output of the rectifier circuit 44A becomes larger than the output of the rectifier circuit 44B, and the differential amplifier 45 outputs a rotational torque detection signal having a positive value.

On the other hand, if you select reverse range with the select lever,
When the reverse clutch 11 is engaged, the low-and-reverse brake 14 is activated, and the rotational force transmitted to the input shaft is transmitted to the reverse clutch 11 and the sun gear 9a of the front planetary gear 9.

It is transmitted to the output shaft 17 via the pinion gear 9b, internal gear 9d, and planet carrier 8C of the rear planetary gear 8, and the output shaft 17 rotates in the opposite direction. As a result, the first group row 32A undergoes tensile deformation in the direction shown by ■-■ in FIG. 6, and the second group row 32B undergoes compressive deformation in the direction shown by ■-■ in the same figure. receive.

As a result, in the first group row 32A, the magnetic permeability increases, so the inductance L1 increases, whereas in the second group row 32B, the i3 magnetic permeability decreases, so the inductance L2 decreases.

Therefore, in the bridge circuit 40 of the measuring section 30C, the voltage of the output on the output terminal db side is higher than the output on the output terminal cb side. Therefore, in the signal processing section 43,
The output of the rectifier circuit 44B becomes larger than the output of the rectifier circuit 44A, and a torque detection signal having a negative value is output from the differential amplifier 45.

Therefore, when the above-mentioned measurement is performed for various rotational torques for each rotational direction of the output shaft 17, the value of the rotational torque applied to the output shaft 17 and the first . second group column 32A,
Since there is a proportional relationship with the magnetic permeability value of 32B, the 8th
The results shown in the figure are obtained. That is, when the rotational torque is zero, the output voltage of the signal processing section 43 is zero, and when rotational torque is applied in the clockwise or counterclockwise direction from this state, a positive or negative voltage proportional to the torque value is applied. Output voltage is obtained. In other words, the magnitude of the rotational torque input to the output shaft 17 can be determined by the value of the output voltage, and the direction in which the rotational torque is applied can be determined by the positive or negative value of the output voltage. By performing feedback control of engagement elements such as clutches, shift shock can be prevented and optimum shift control can be performed.

In particular, since the rotational torque of the output shaft can be detected near the part where the rotational torque is transmitted, the rotational torque can be detected accurately and response delays in feedback control can be reduced. .

This embodiment has various advantages because it is configured and operates as described above.

First, the torque detection surface 30A is connected to the small diameter portion 31 of the output shaft 17.
Groups a, ..., a and a, ... directly on the outer peripheral surface of
, b, and because the output shaft 17 is composed of a single member that utilizes its own magnetic properties, the processing process is simplified and the cost is lower than when a magnetostrictive thin film is attached. In addition, it is mechanically robust, and there is no difference in thermal expansion coefficient between the members, which is the case with composite members to which magnetostrictive thin films are attached, and the temperature characteristics are improved. In addition, since the torque detection surfaces 30A are each formed over the circumferential surface in a predetermined area, the detection output is averaged in the circumferential direction, and the detection output is averaged in the circumferential direction, thereby detecting local magnetic characteristics such as structural defects inside the output shaft 17. Since it is not directly affected by disturbances, and even if eccentricity occurs in the output shaft 17, the effects of this eccentricity error can be canceled out on both sides of the output shaft 17, the torque detection accuracy can be significantly improved. .

Furthermore, in this embodiment, the torque detection surface 30A is configured such that the two group rows 32A and 32B receive deformation forces in mutually opposite directions with respect to rotational torque, so that output signals of opposite polarity can be obtained. As a result, the range width of the detection signal for changes in torque can be set wide, and both clockwise and counterclockwise rotations can be detected while maintaining the high sensitivity described above.

Furthermore, in this embodiment, the first. Second coil 33A
33B is configured to be unnecessary for both excitation and detection, the size can be further reduced compared to the case where both coils are wound separately.

In the above-described embodiment, the first torque detection surface is used as the first torque detection surface. Although the case where the second group rows 32A and 32B are provided has been described, the present invention is not necessarily limited to this, and for example, only one of the above-mentioned rows is provided.
It is also possible to simplify the configuration, in which case the measurement section 30C can be bridged! Depending on how 40 is assembled, it becomes possible to measure the rotational torque of one or both of them as appropriate. On the other hand, in the above case, if there is sufficient mounting space, multiple sets of torque detection surfaces 30A and torque detectors 30B each having shape magnetic anisotropy in the same direction may be provided to thicken the detection output. However, the detection accuracy may be further improved.

Furthermore, in the embodiment described above, groups a, . . .

Although the inclination angles of a,..., b are set to +45 degrees and -45 degrees, respectively, the present invention is not necessarily limited to this, and for example, the inclination angles may be opposite to each other, Further, the angle may be other than 45 degrees depending on the needs of processing and the like.

Furthermore, although the above-mentioned measuring section 30C measures the output voltage according to the rotational torque, the output voltage can also be digitized and processed by a microcomputer to control the speed change of the power train system.

By the way, in the present invention, the groups are provided obliquely as the magnetic flux direction defining means constituting the shape magnetic anisotropy.
As a variation of this, a group of non-magnetically permeable members may be embedded to reduce leakage of magnetic flux and to make the diagonal passage of magnetic flux more reliable.

Further, in the above embodiment, the case where the torque detection surface is formed directly on the output shaft has been described, but the present invention is not limited to this. You can do it like this.

In addition, not only when the rectifier circuits 44A and 44B are used as the measuring section, but also when an AC differential amplifier is used as the differential amplifier, the output terminals c and d of the bridge circuit 40 are directly connected to the input terminals of the differential amplifier. (In short, it is sufficient if the structure is such that the balanced state and unbalanced state of the output terminals c and d of the bridge circuit 44 can be detected.)

Furthermore, the automatic modification machine is not limited to the configuration of the above embodiment, but the present invention can be applied to automatic modification machines with any other configuration.

(Effects of the Invention) As explained above, according to the present invention, a torque detection surface is formed on the rear side of the rotational torque transmission part in the transmission case of the output shaft of an automatic modification machine, and the torque detection surface is Since the torque detector with opposing detection coils is arranged on the cylindrical member on the transmission case side, it is possible to detect the rotational torque transmitted to the output shaft near the transmission part, without contact. It is possible to accurately detect the rotational torque transmitted to the output shaft and the shift shock that occurs when tightening the fastening elements of the automatic modification machine, and it is also possible to reduce the detection delay of rotational torque. It is possible to provide a torque detection device suitable for controlling the speed change of an automatic modification machine using the detected torque value.

Additionally, since the output shaft torque detector is located inside the transmission case, the output shaft torque can be reliably detected even when a sub-transmission or transfer is directly connected to the downstream side of the automatic modification machine. .

Furthermore, since the torque detection device can be placed in a narrow space, the overall length of the transmission case does not become long, and special brackets, etc. are not required when attaching the torque detector to the cylindrical member on the transmission case side. First, since the output shaft and the transmission case side cylindrical member are arranged concentrically, it is possible to maintain a uniform gap between the detection coil of the torque detector and the torque detection surface.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an embodiment of the present invention, Fig. 2 is a partially enlarged view of the main part of Fig. 1, Fig. 3 is a sectional view taken along the line mm in Fig. 2, and Fig. 4 is Schematic diagram of the automatic modification machine in Figure 1, Figure 5
The figure is a block diagram showing an example of the measurement unit, Figure 6 is a developed view showing the torque detection surface formed on the output shaft, Figure 7 is an explanatory diagram showing the state of the magnetic field generated by the coil, and Figure 8 is torque detection. FIG. 3 is a characteristic diagram showing the relationship between the torque and output voltage of the device. In the figure, 1 is the transmission case, 6 is the input shaft, and 8
is the rear planetary gear, 9 is the front planetary gear, IO is the high clutch, 11 is the reverse clutch, 1
2 is a forward one-way clutch, 13 is a forward clutch, 14 is an overrun clutch, 15 is a low and reverse brake, 16 is a row one-way clutch, 17 is an output shaft, 20 is a cylindrical member, 30A is a torque detection surface, 30B is a torque detection instrument, 30G is the measuring section, 32A,
'32B is a group row, 33A, 33B are coils, 40
is a bridge circuit, and 45 is a differential amplifier.

Claims (1)

[Claims] In an automatic modification machine in which driving force from an engine is transmitted via an input shaft, and the driving force is automatically shifted and transmitted to an output shaft by appropriately selecting a plurality of fastening elements, the drive power is transmitted to the output shaft within a transmission case of the output shaft. A torque detection surface having shape magnetic anisotropy is formed on the outer circumferential surface of the fastening element at a stage subsequent to the final stage, and a torque detector having a detection coil is mounted on a cylindrical member on the transmission case side facing the torque detection surface. A torque detection device for an automatic transmission, which is characterized by: