JP2002354885A - Electric actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve durability of a position (rotating angle) detecting unit in an electric actuator with a position (rotating angle) detector. SOLUTION: A pattern plate 153 is provided in the side of an output shaft 127. Consequently, since a sliding distance of the first and second brushes 155, 156 and the first and second pulse patterns 151, 152 can be shortened, a relative sliding velocity of the first and second brushes 155, 156 for the first and second pulse patterns can be reduced. Accordingly, wear of the first and second brushes 155, 156 and first and second pulse patterns 151, 152 can be controlled. As a result, durability of actuator 100 can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric actuator having a speed reduction mechanism, and is effective when applied to an electric actuator for driving a movable member such as an air mix door and a mode switching door of a vehicle air conditioner.

[0002]

2. Description of the Related Art In an electric actuator for driving a movable member such as an air mix door or a mode switching door of a vehicle air conditioner disclosed in Japanese Patent Application Laid-Open No. 12-358396, the input shaft of a speed reducer is proportional to the rotation angle of the motor. A pulse generator for generating a predetermined number of pulses is provided, and the rotation angle is detected by counting the number of pulses.

[0003]

By the way, in the invention described in the above publication, a pulse pattern plate (hereinafter abbreviated as a plate) provided with a pulse pattern composed of conductive portions and non-conductive portions alternately arranged in the circumferential direction. ) And an electrical contact (brush) that contacts the pulse pattern, a pulse signal (pulse current) generated when the electrical contact comes into contact with the conductive part by rotating the plate in conjunction with the electric motor. ) Is counted and the rotation angle is detected. Hereinafter, this detection method is referred to as a contact pulse signal method.

However, in the invention described in the above-mentioned publication, since the plate is provided on the input side of the speed reducer, the sliding distance between the electric contact and the pulse pattern becomes relatively long, and the electric resistance to the pulse pattern is increased. There is a problem that the relative sliding speed of the contacts becomes relatively high, the amount of wear of the electrical contacts and the pulse pattern increases, and the durability of the electric actuator decreases.

[0005] In view of the above, an object of the present invention is to improve the durability of an electric actuator.

[0006]

According to the first aspect of the present invention, there is provided an electric motor having an electric motor (110) and a plurality of gears. A drive unit (130) including a speed reduction mechanism (120) for reducing and outputting the rotational force input from the motor (110)
And the electric motor (110) of the speed reduction mechanism (120)
Angle detection means (2) for detecting a rotation angle with an output gear installed on the output side of an input gear directly driven by the
20), and the rotation angle detecting means (220) detects the rotation angle based on two types of pulse signals having different phases generated according to the rotation angle of the output gear.

As a result, the sliding distance can be shortened as compared with the prior art, so that the relative sliding speed can be reduced and the durability of the electric actuator can be improved.

[0008] According to the second aspect of the present invention, there is provided a reduction mechanism configured to include the electric motor (110) and a plurality of gears, and to reduce and output the rotational force input from the electric motor (110). A drive unit (130) comprising (120)
And the electric motor (110) of the speed reduction mechanism (120)
Rotation angle detection means (220) for detecting a rotation angle on the output side of the input gear driven directly by the rotation angle detection means, and the rotation angle detection means (220) has two types of phases generated in accordance with the rotation angle. The rotation angle is detected based on the pulse signal.

As a result, the sliding distance can be reduced as compared with the prior art, so that the relative sliding speed can be reduced and the durability of the electric actuator can be improved.

The pulse generating means (158) for generating a pulse signal comprises conductive parts (151a, 152a) and non-conductive parts (151b, 151b, A pulse pattern plate (153) provided with first and second pulse patterns (151, 152) composed of the first pulse pattern (1
51) and a second electrical contact (15) contacting the second pulse pattern (152).
6), and the pulse generating means (15
8) may be configured to generate two types of pulse signals having different phases by shifting the phase of the first pulse pattern (151) and the phase of the second pulse pattern (152).

The pulse generating means (158) for generating a pulse signal may include a conductive part (151a, 152a) and a non-conductive part (151b, 152b) extending in the radial direction. A pulse pattern plate (153) having pulse patterns (151, 152) alternately arranged in the circumferential direction;
51, 152) contacting the first and second electrical contacts (155, 152).
156), and the first electrical contact (1
55) and a contact point (P1) between the pulse pattern (151, 152) and a contact point (P2) between the second electrical contact (156) and the pulse pattern (151, 152) in the circumferential direction and the radial direction. A configuration may be made such that two types of pulse signals having different phases are generated by shifting.

According to the fifth aspect of the present invention, the conductive portion (15) with respect to the rotation center of the pulse pattern plate (153) is provided.
1a, 152a) and the non-conductive portions (151b, 152b) have the same circumferential angle (β1, β2), and the phase difference of the pulse signal is equal to the conductive portion (151, 152a).
a, 152a) is substantially half the circumferential angle (α1, α2).

As a result, there are four combinations (output signal patterns) of two types of pulse signals (A-phase pulse and B-phase pulse) as shown in FIG. 7 described later. Therefore, it is possible to clearly determine which signal of the A-phase pulse and the B-phase pulse is input first by the output signal pattern, so that the direction of rotation can be easily determined.

According to the present invention, the conductive portion (15)
The common conductive portion pattern (154) electrically connected to 1a, 152a) is provided on the inner peripheral side of the pulse pattern (151, 152) in the pulse pattern plate (153).

Thus, the pulse pattern (151, 1
Since the sliding radius of 52) can be increased, a change in the rotation angle with respect to the same pitch fluctuation is reduced, and the detection accuracy of the rotation opening can be improved.

Incidentally, the reference numerals in parentheses of the above means are examples showing the correspondence with specific means described in the embodiments described later.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment)
FIG. 1 is a schematic view of a vehicle air conditioner 1 in which an electric actuator (hereinafter, abbreviated as an actuator) according to the present invention is applied to an air door of a vehicle air conditioner 1 of a vehicle equipped with a water-cooled engine.

An air conditioning casing 2 forming an air flow path
An air inlet 3 for sucking the air inside the vehicle and an external air inlet 4 for sucking the outside air are formed at the upstream side of the vehicle, and these inlets 3 and 4 are selectively opened and closed. A suction port switching door 5 is provided. The inlet switching door 5 is opened and closed by driving means such as a servomotor or by manual operation.

A blower 7 is provided at a downstream side of the inlet switching door 5, and the air sucked from both the inlets 3 and 4 by the blower 7 is supplied to each outlet 14, which will be described later.
It is blown toward 15 and 17. An evaporator 9 serving as an air cooling means is provided downstream of the air from the blower 7, and all the air blown by the blower 7 is discharged from the evaporator 9.
Pass through. A heater core 10 serving as air heating means is provided downstream of the evaporator 9 in the air. The heater core 10 heats the air using the cooling water of the engine 11 as a heat source.

A bypass passage 12 for bypassing the heater core 10 is formed in the air-conditioning casing 2, and a heater core 10 is provided upstream of the heater core 10 in the air.
An air mix door 13 that adjusts the ratio of the amount of air flowing through the air passage to the amount of air flowing through the bypass passage 12 is provided. The air flow rate is adjusted by adjusting the opening of the air mix door 13 by the actuator 100 (details will be described later) according to the present embodiment.

At the most downstream side of the air-conditioning casing 2, there are provided a face outlet 14 for blowing air-conditioned air to the upper body of the passenger in the passenger compartment, and a foot outlet 15 for discharging air to the feet of the passenger in the passenger compartment. Defroster outlet 1 for blowing air toward the inner surface of windshield 16
7 are formed.

The air outlet mode switching door 1 is located at the upstream side of each of the air outlets 14, 15, 17 respectively.
8, 19, and 20 are provided, and these blowout mode switching doors 18, 19, and 20 are opened and closed by driving means such as a servomotor.

Next, referring to FIG.
0 will be described.

Reference numeral 110 denotes an electric motor (hereinafter, abbreviated as a motor) that rotates by receiving electric power from a battery (not shown) mounted on the vehicle, and 120 decelerates the rotational force input from the motor 110. This is a reduction mechanism that outputs the air toward the air mix door 13. Hereinafter, the rotating and driving mechanism units such as the motor 110 and the speed reduction mechanism 120 will be referred to as a driving unit 130.
Call.

Incidentally, the speed reduction mechanism 120 is
Is a gear train composed of a worm 121 press-fitted into the output shaft 111, a worm wheel 122 meshing with the worm 121, and a plurality of spur gears 123 and 124, and a final stage gear (output side gear) 126 located on the output side. In
An output shaft 127 is provided.

Reference numeral 140 denotes a housing for accommodating the driving unit 130 and brushes (electric contacts) 155 to 157 to be described later.
Is a fixed casing.

The input gear (worm 12) of the speed reduction mechanism 120, which is directly driven by the motor 110,
1) On the output side (output shaft 127), a pulse pattern plate (hereinafter referred to as a pattern plate) 153 is provided as shown in FIGS. The plate 153 includes conductive portions 151a and 152a and non-conductive portions 15 alternately arranged in the circumferential direction.
First and second pulse patterns 15 composed of 1b and 152b
1, 152 are provided, and rotate integrally with the output shaft 127.

At this time, the circumferential angles α1, α2 of the conductive portions 151a, 152a and the circumferential angles β1, β2 of the non-conductive portions 151b, 152b are made equal to each other, and the phase of the first pulse pattern 151 is changed to the second pulse pattern. With respect to the phase 152, the circumferential angles α1, α2 (= the circumferential angles β1, β2) are shifted by approximately 1/2.

The first and second pulse patterns 151, 1
52 is electrically connected, and the first and second pulse patterns 151 and 152 are electrically connected to a common pattern (common conductive portion pattern) 154 provided on the inner peripheral side of the both pulse patterns 151 and 152, Brush 15 described later
7, and is electrically connected to a negative electrode side of a battery (not shown).

On the other hand, on the casing 140 side, first to third brushes (electric contacts) 155 made of a copper-based conductive material connected to the positive electrode side of the battery via a printed circuit board (not shown).
157 are fixed, the first brush 155 contacts the first pulse pattern 151, and the second brush 156
The third brush 157 is configured to be in contact with the pulse pattern 152 and the common pattern 154.

In this embodiment, the first to third brushes 1
By setting the number of contact points between 55 to 157 and the pattern plate 153 at two or more (four in this embodiment), the first
To 3 brushes 155 to 157 and conductive portions 151a and 152a
(Including the common pattern 154).

Next, the general operation of the actuator 100 will be described.

FIG. 6 is a schematic diagram showing an electric control circuit 200 of the actuator 100.
Comprises a motor drive circuit 210 for driving the motor 110, a rotation angle detector (rotation angle detection means) 220 for detecting the rotation angle and the direction of rotation of the output shaft 127 based on a pulse signal generated by the pattern plate 153, and the like. Have been.

Then, the motor 110 rotates and the output shaft 1
When 27 (pattern plate 153) rotates, the first,
An energized (ON) state in which the second brushes 155 and 156 contact the conductive portions 151a and 152a;
Non-conducting (OFF) states in which the non-conductive portions 151b and 152b are in contact with the non-conductive portions 5 and 156 occur periodically.

Therefore, the first and second brushes 155, 15
7, a pulse signal is generated each time the motor 110 rotates by a predetermined angle as shown in FIG.
27 rotation angles can be detected.

As is apparent from the above description, in the present embodiment, the pulse generator which generates a pulse signal every time the output shaft 127 rotates by a predetermined angle by the first and second brushes 155 and 156 and the pattern plate 153. (Pulse generating means) 158 (see FIG. 6).

Further, since the phase of the first pulse pattern 151 and the phase of the second pulse pattern 152 are shifted,
In the pulse generator 158, a pulse signal generated by the first pulse pattern 151 and the first brush 155 (hereinafter, referred to as a pulse signal).
This pulse signal is called an A-phase pulse. ) And A generated by the second pulse pattern 152 and the second brush 156.
A pulse signal whose phase is shifted (different) from the phase pulse (hereinafter, this pulse signal is referred to as a B-phase pulse) is generated.

Therefore, in the present embodiment, the rotation direction of the motor 110 (output shaft 127) is detected based on which of the A-phase pulse and the B-phase pulse is input to the rotation angle detector 220 first. are doing.

Next, the features (effects) of this embodiment will be described.

In this embodiment, the pattern plate 153
Are provided on the output shaft 127 side, so that the first and second brushes 155 and 156 and the first and second pulse patterns 151 and 1 are provided.
The sliding distance with the reference numeral 52 can be reduced as compared with the related art. Therefore, the first and second pulse patterns 151, 1
52, the relative sliding speed of the first and second brushes 155 and 156 can be reduced.
55, 156 and first and second pulse patterns 151, 15
2 can be suppressed, and the actuator 100
Can be improved in durability.

Further, in the present embodiment, the B-phase pulse is applied to the A-phase pulse by the circumferential angles α1, α1 of the conductive portions 151a and 152a.
Since there is a shift of approximately 1/2 of α2, there are four combinations (output signal patterns) of the A-phase pulse and the B-phase pulse as shown in FIG. Therefore, any one of the signals of the A-phase pulse and the B-phase pulse is supplied to the rotation angle detector 220 first.
Can be clearly determined by the output signal pattern.

That is, the output signal pattern is 1 → 2 → 3 →
The case of repeating in the order of 4 → 1 and the case of 4 → 3 → 2 → 1 → 4
, The direction of rotation of the output shaft 127 can be easily determined.

Further, since the common pattern (common conductive portion pattern) 154 provided on the inner peripheral side of both the pulse patterns 151 and 152 is provided,
Since the sliding radius of 1, 152 can be increased,
The change in the rotation angle with respect to the same pitch change becomes small, and the detection accuracy of the rotation opening can be improved.

(Second Embodiment) In the first embodiment, the first
Phase of pulse pattern 151 and second pulse pattern 15
In this embodiment, the phase of the A-phase pulse and the phase of the B-phase pulse are shifted by shifting the phase of the second pulse pattern 151 from the first pulse pattern 151 and the second pulse pattern 152, as shown in FIG. The first brush 155 and the first pulse pattern 15 are provided on the pulse plate 153 in the same phase.
1 and a contact point P2 between the second brush 156 and the second pulse pattern 152 in the circumferential and radial directions to generate two types of pulse signals having different phases. Things.

Third Embodiment In the above-described embodiment, the first to third brushes 155 to 157 are fixed to the casing 140, and the pulse plate 153 rotates together with the output shaft 127. Contrary to this, as shown in FIG.
157 is rotated together with the output shaft 127, and the pulse plate 153 is fixed to the casing 140.

(Other Embodiments) In the above embodiment, the pulse generator 158 is provided on the output shaft 127. However, the present invention is not limited to this. For example, the pulse generator 158 (pulse plate 153) For this purpose, a rotating section which is further decelerated may be provided to generate a pulse signal.

In the above-described embodiment, the pattern plate 153 is formed by a printed circuit board. However, the present invention is not limited to this. For example, a conductive member is directly plated on a gear forming the reduction gear 120. Alternatively, the pattern plate 153 may be formed by pressing a metal plate.

In the above-described embodiment, the common pattern (common conductive portion pattern) 154 provided on the inner peripheral side of both the pulse patterns 151 and 152 is provided. However, the present invention is not limited to this. , Both pulse patterns 1
The common pattern 154 may be provided on the outer peripheral side of the pulse patterns 51 and 152, or the common pattern 154 may be provided between the pulse patterns 151 and 152.

In the above embodiment, the electric actuator according to the present invention is applied to the air mix door 13, but the present invention is also applied to other movable members such as the blowout mode switching doors 18, 19, and 20. can do.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a vehicle air conditioner.

FIG. 2 is a schematic diagram of the electric actuator according to the first embodiment of the present invention.

FIG. 3A is a front view of a pulse plate according to the first embodiment of the present invention, and FIG. 3B is a side view of FIG.

FIG. 4 is a sectional view taken along line AA of FIG. 2;

FIG. 5 is an enlarged view of a pulse plate according to the first embodiment of the present invention.

FIG. 6 is a schematic diagram illustrating a control circuit of the electric actuator according to the first embodiment of the present invention.

FIG. 7 is a pulse signal chart of the electric actuator according to the first embodiment of the present invention.

FIG. 8 is an enlarged view of a pulse plate according to a second embodiment of the present invention.

FIG. 9A is a front view of a brush of an electric actuator according to a third embodiment of the present invention, and FIG. 9B is a front view of a pulse plate of the electric actuator according to the third embodiment of the present invention. .

[Explanation of symbols]

100: electric actuator, 110: electric motor, 1
20: reducer, 127: output shaft, 151: first pulse pattern, 152: second pulse pattern, 153: pulse pattern plate, 154: common pattern, 155 ...
1st brush, 156 ... 2nd brush, 157 ... 3rd brush.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Seiji Tateishi 390 Umeda, Kosai-shi, Shizuoka Prefecture Asmo Stock Company In-house F-term (Reference) DD03 DD19 EE32 FF01 HH01 HH05

Claims (6)

[Claims] A speed reduction mechanism (12) configured to include an electric motor (110) and a plurality of gears, and to reduce and output a rotational force input from the electric motor (110).
0), and the electric motor (11) of the speed reduction mechanism (120).
0) a rotation angle detecting means (220) for detecting a rotation angle with an output gear provided on the output side of the input gear directly driven by the output gear, wherein the rotation angle detecting means (220) is provided with the output gear. An electric actuator for detecting a rotation angle based on two types of pulse signals having different phases generated according to the rotation angle of the electric actuator. 2. A speed reduction mechanism (12) comprising an electric motor (110) and a plurality of gears, and configured to reduce and output the rotational force input from the electric motor (110).
0), and the electric motor (11) of the speed reduction mechanism (120).
0) a rotation angle detecting means (220) for detecting a rotation angle on the output side of the input gear driven directly by the input gear, wherein the rotation angle detection means (220) detects a phase generated according to the rotation angle. An electric actuator, wherein a rotation angle is detected based on two different types of pulse signals. 3. A pulse generating means (158) for generating the pulse signal comprises conductive parts (1) alternately arranged in a circumferential direction.
51a, 152a) and non-conductive portions (151b, 152)
b) first and second pulse patterns (151, 15)
Pulse pattern plate (153) provided with 2)
A first electrical contact (155) contacting the first pulse pattern (151); and a second electrical contact (15).
2) and a second electrical contact (156) that contacts the second pulse pattern (156). Further, the pulse generating means (158) is configured to control the phase of the first pulse pattern (151) and the second pulse pattern (156). The electric actuator according to claim 1 or 2, wherein two types of pulse signals having different phases are generated by shifting the phase of (152). 4. A pulse generating means (158) for generating the pulse signal comprises a pulse formed by arranging conductive portions (151a, 152a) and non-conductive portions (151b, 152b) extending in a radial direction alternately in a circumferential direction. A pulse pattern plate (153) having a pattern (151, 152); and first and second electrical contacts (155, 156) contacting the pulse pattern (151, 152). A contact point (P1) between the first electrical contact (155) and the pulse pattern (151, 152); a second electrical contact (156) and the pulse pattern (151, 152);
3. The method according to claim 1, wherein two kinds of pulse signals having different phases are generated by shifting the contact point (P2) with the contact point (152) in the circumferential direction and the radial direction. Electric actuator. 5. The pulse pattern plate (153).
The conductive portion (151a, 152a) with respect to the rotation center of
And the non-conductive portion (151b,
152b) have the same circumferential angle (β1, β2), and the phase difference of the pulse signal is
5. The electric actuator according to claim 3, wherein the circumferential angle (α1, α2) of 1a, 152a) is approximately 略. 6. The common conductive part pattern (154) electrically connected to the conductive parts (151a, 152a) is located on the inner peripheral side of the pulse pattern (151, 152) in the pulse pattern plate (153). The electric actuator according to claim 3, wherein the electric actuator is provided.