JP3919396B2 - Throttle opening sensor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a throttle opening sensor, and more specifically, a wear powder generated at a sliding contact portion between a rotor and a cover member is not scattered in a sensor case, and a substrate on which an electric circuit is formed is provided. The present invention relates to a throttle opening sensor that can be surely positioned and fixed.
[0002]
[Prior art]
A schematic longitudinal section of a throttle opening sensor according to the prior art is shown in FIG. In this throttle opening sensor 1, a housing 3 having a rotor insertion hole 2 at the bottom, and a cover member 4 having a side wall portion 4 a that covers the side wall portion 3 a of the housing 3 and seals the open portion of the housing 3. A sensor case 5 is configured.
[0003]
A rotor 6 is rotatably inserted into the rotor insertion hole 2 of the housing 3. The rotor 6 includes a rotating portion 7 and a bush 8 fitted to the rotating portion 7. Among these, the rotating portion 7 is connected to a shaft (not shown) of a throttle valve of an automobile, for example. . Further, an annular convex portion 10 is formed so as to protrude from the central portion of the horizontal end surface 9 of the bush 8. The lower surface of the horizontal end surface 9 of the bush 8 is rotatably supported by an annular bearing portion 11 that rises vertically from the bottom surface of the housing 3. The diameter of the horizontal end surface 9 of the bush 8 is larger than the diameter of the rotor insertion hole 2, and thus the rotor 6 is prevented from coming off from the rotor insertion hole 2.
[0004]
Two brushes (contacts) 12 a and 12 b are fixed to the upper surface of the horizontal end surface 9 of the bush 8, and the brushes 12 a and 12 b are connected to two resistors 14 a and 14 b provided on the lower surface of the substrate 13. Make sliding contact. The contact portions 16a to 16c of the three terminal plates 15a to 15c are in contact with the ends of the resistors 14a and 14b, and the external terminal connection portions 17a to 17c of the terminal plates 15a to 15c are illustrated in the figure. External terminals that are not connected are electrically connected.
[0005]
A through hole 18 is formed in the substrate 13, and the resistors 14 a and 14 b are formed so as to surround a part of the through hole 18 with the center of the through hole 18 as a reference position. The annular protrusion 10 of the bush 8 passes through the through hole 18.
[0006]
On the other hand, on the ceiling surface of the cover member 4, the protruding portion 19 and the three supporting protrusions {in FIG. 3, two of these (20a, 20b) are illustrated. } And pressing protrusions 21a and 21b are provided. Among these, the protruding portion 19 is inserted into the annular convex portion 10 of the bush 8.
[0007]
The support protrusions 20a and 20b and a support protrusion (not shown) are formed so as to surround and sandwich the substrate 13 at positions rotated by 120 ° each other. By this clamping, the substrate 13 is positioned and fixed to the cover member 4. Further, in this state, the substrate 13 is pressed by the pressing protrusions 21a and 21b, so that the resistors 14a and 14b reliably come into contact with the brushes 12a and 12b.
[0008]
A coil spring 22 is interposed between the lower surface of the horizontal end surface 9 of the bush 8 and the bottom surface of the housing 3, and the rotor 6 is directed toward the substrate 13 by the elastic biasing force of the coil spring 22. Is pressed.
[0009]
In the throttle opening sensor 1 configured as described above, when the throttle valve is opened and the shaft of the throttle valve is rotationally displaced, the rotor 6 is rotated following this. As a result, the brush 12a, 12b slides on the surface of the resistor 14a, 14b, so that the resistance value between the three terminal plates 15a-15c changes according to the amount of rotation of the rotor 6. By converting the change in the resistance value, the opening of the throttle valve is detected.
[0010]
[Problems to be solved by the invention]
Incidentally, as described above, when the rotor 6 rotates, the inner peripheral wall of the annular convex portion 10 of the bush 8 and the protruding portion 19 of the cover member 4 are in sliding contact with each other. As a result, wear powder is generated, and the wear powder is scattered in the sensor case 5. In this case, for example, if scattered wear powder adheres to the surfaces of the resistors 14a and 14b, the resistance value between the terminal plates 15a to 15c when the brushes 12a and 12b are in sliding contact is the value before the wear powder is attached. This causes a problem such that the opening degree of the throttle valve cannot be accurately detected.
[0011]
Further, as described above, the substrate 13 is positioned and fixed by being surrounded and sandwiched by the support protrusions 20a and 20b of the cover member 4 and a support protrusion (not shown). May not be detected accurately. That is, since the resistors 14a and 14b are formed on the substrate 13 with the center of the through hole 18 as a reference position, when the through hole 18 is deviated from a predetermined position due to a dimensional error or the like, the center of the through hole 18 is obtained. This is because the rotation center of the rotor 6 shifts and the brushes 12a and 12b do not slide in contact with the resistors 14a and 14b at predetermined positions.
[0012]
The present invention has been made to solve the above-described problem, and does not scatter the abrasion powder generated at the sliding contact portion between the rotor and the cover member inside the sensor case, and the substrate is securely positioned and fixed. Thus, an object of the present invention is to provide a throttle opening sensor that can accurately detect the opening of the throttle valve.
[0013]
[Means for Solving the Problems]
In order to achieve the above object, a throttle opening sensor according to the present invention includes a housing having a rotor insertion hole,
A rotor inserted into the rotor insertion hole and rotated in accordance with the rotational displacement of the throttle valve shaft, and having a first annular convex portion;
A contact fixed to the rotor;
A substrate having a through-hole and formed with a resistor to which the contact is in sliding contact;
A terminal plate in contact with the resistor;
A cover member having a second annular protrusion provided at a position surrounding the sealed opening of the housing and hollow projection and projecting portion,
With
The resistor has a portion extending along the periphery of the through hole,
The substrate is positioned by fitting a second annular convex portion of the cover member into the through hole,
The protruding portion of the cover member is inserted into the first annular convex portion of the rotor passed through the through hole in a state where its center substantially coincides with the center of the through hole, and the first of the rotor The annular convex portion is surrounded by the second annular convex portion of the cover member , and the inner wall of the first annular convex portion of the rotor , which is a sliding contact portion, and the side wall of the protruding portion of the cover member are the first and the second. Sealed by the second annular projection ,
Abrasion powder generated in the sliding portion, characterized that you accommodated in an internal space provided in the projecting portion of the cover member.
[0014]
With such a configuration, the abrasion powder generated at the sliding contact portion between the rotor and the cover member is captured by the second annular convex portion that seals the sliding contact portion. For this reason, it is avoided that abrasion powder scatters in a sensor case.
[0015]
In this case, the abrasion powder generated at the sliding contact portion is accommodated in the internal space provided in the protruding portion of the cover member . Thereby, it is possible to more reliably avoid wear powder from being scattered in the sensor case.
[0016]
In this case, since the rotation center of the rotor and the central axis of the resistor formed on the substrate coincide with each other in order to support the substrate by the second annular convex portion of the cover member, the contact is on the resistor. The sliding contact is surely made at a predetermined position. Therefore, the opening degree of the throttle valve can be detected with high accuracy.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the throttle opening sensor according to the present invention will now be described in detail with reference to the accompanying drawings.
[0018]
A schematic configuration of a throttle opening sensor according to the present embodiment is shown in FIG. 1 as an exploded perspective view, and a schematic longitudinal section is shown in FIG. As shown in these drawings, the throttle opening sensor 30 includes a housing 38 having a bearing portion 34 in which a rotor insertion hole 32 is formed and an upper end being an opening portion 36, and an opening portion of the housing 38. A sensor case 42 is constituted by a cover member 40 that seals 36, and a substrate 50 on which a coil spring 44, a rotor 46, and two resistors 48a and 48b are formed is accommodated in the sensor case 42. ing.
[0019]
A small-diameter portion 52 having a smaller diameter than the opening above the rotor insertion hole 32 (on the cover member 40 side) is formed in the rotor insertion hole 32 formed in the annular bearing portion 34 that rises vertically from the bottom surface of the housing 38. Is provided. An annular recess 54 is formed around the bearing portion 34, and a locking groove 56 is provided on the side wall 54 a of the annular recess 54 by cutting out a part of the side wall 54 a.
[0020]
Three terminal plates 60a to 60c having contact portions 58a to 58c that are in contact with the resistors 48a and 48b on the substrate 50 are installed at the linear end portion of the housing 38, and the respective terminal plates 60a to 60c are provided. The one end portions 62a to 62c extend to the inside of the external terminal connection port 64 (see FIG. 2), and are electrically connected to an external terminal (not shown) inserted into the external terminal connection port 64.
[0021]
In addition, inside the housing 38, a substrate placement portion 66 for placing the substrate 50 and a cover member placement portion 68 for placing the cover member 40 are provided.
[0022]
One end portion of the coil spring 44 is provided with a tongue piece 70 having one end portion bent toward the outside of the circumference, and the tongue piece 70 is locked in the locking groove 56 described above. . A hook 72 is provided at the other end of the coil spring 44, and this hook 72 is engaged with a key groove 78 formed by cutting out a part of a horizontal end surface 76 of a bush 74 described later of the rotor 46. It has been stopped.
[0023]
As will be understood from FIG. 2, the rotor 46 includes a rotating portion 80 and a bush 74 fitted to the rotating portion 80. The rotating portion 80 is, for example, a shaft (not shown) of a throttle valve of an automobile. It is connected to. A web washer 82 is fitted to the side wall of the bush 74.
[0024]
An annular convex portion 84 is formed so as to protrude substantially at the center of the horizontal end surface 76 of the bush 74. The inner bottom surface of the annular convex portion 84 is positioned lower than the horizontal end surface 76 (see FIG. 2).
[0025]
Two brushes (contactors) 86 a and 86 b are fixed to the upper surface of the horizontal end surface 76. That is, the brushes 86a and 86b are joined to the tip of the pedestal 88, and the pedestal 88 is screwed to the bush 74 by screws 90a and 90b. These brushes 86 a and 86 b are in sliding contact with resistors 48 a and 48 b (see FIG. 1) formed on the lower surface of the substrate 50 having the through holes 92.
[0026]
The resistors 48a and 48b will be specifically described with reference to FIG. First, the resistor 48a formed inside is electrically connected to the conductor 94a. That is, the conductor 94a is concentric with a substantially square terminal plate contact portion 96a with which the contact portion 58b of the central terminal plate 60b contacts among the three terminal plates 60a to 60c installed in the housing 38. , And the terminal plate contact portion 96a and the annular portion 98a are electrically connected by the conducting portion 100a. The resistor 48a is interposed in the annular portion 98a.
[0027]
On the other hand, the resistor 48b formed outside the resistor 48a is electrically connected to the conductor 94b formed outside the conductor 94a. That is, the conductor 94b has two terminal plate contact portions 96b and 96c that contact the contact portions 58a and 58c of the terminal plates 60a and 60c, respectively, and an annular portion 98b that concentrically surrounds the annular portion 98a. The terminal plate contact portions 96b and 96c and the annular portion 98b are electrically connected by the conducting portions 100b and 100c. The resistor 48b is interposed in the annular portion 98b. That is, the central axis of the resistors 48 a and 48 b is the center of the through hole 92.
[0028]
The resistors 48a and 48b and the conductors 94a and 94b can be formed by, for example, screen printing.
[0029]
On the lower surface of the cover member 40, a cylindrical protrusion 104 (see FIG. 2) in which a space 102 is formed, and an annular protrusion that surrounds the protrusion 104 with a predetermined distance from the protrusion 104. 106 is formed.
[0030]
The coil spring 44, the rotor 46, and the substrate 50 are accommodated in the sensor case 42 as follows. Note that the diameter of the annular convex portion 106 is substantially equal to the diameter of the through hole 92 formed in the substrate 50.
[0031]
First, the coil spring 44 is inserted into the annular recess 54 of the housing 38, and the tongue piece 70 of the coil spring 44 is locked in a locking groove 56 formed in the side wall portion 54 a of the annular recess 54.
[0032]
The rotor 46 is rotatably inserted into the rotor insertion hole 32 of the housing 38, and the hook 72 of the coil spring 44 is engaged with the key groove 78 formed on the horizontal end surface 76 of the bush 74 of the rotor 46. Has been. The web washer 82 fitted to the side wall portion of the bush 74 is placed on the upper end surface of the small diameter portion 52 in the bearing portion 34. Further, the side wall portion of the bush 74 and the bearing portion 34 are sealed by a seal member 108 (see FIG. 2).
[0033]
In the substrate 50, the terminal plate contact portions 96a to 96c of the conductors 94a and 94b are in contact with the contact portions 58a to 58c of the terminal plates 60a to 60c, respectively, and the brushes 86a and 86b are in contact with the resistors 48a and 48b, respectively. Thus, the outer peripheral portion of the substrate 50 is placed on the substrate placing portion 66 so as to be separated from the inner wall of the housing 38 by a predetermined distance. That is, the side wall portion 50 a of the substrate 50 is not in contact with the inner wall of the housing 38.
[0034]
When the substrate 50 is placed on the substrate placement portion 66 of the housing 38, the diameter of the through hole 92 formed in the substrate 50 is larger than that of the annular protrusion 84 of the rotor 46. Passes through the through hole 92.
[0035]
Then, the cover member 40 is placed on the cover member placement portion 68 of the housing 38. At this time, the protrusion 104 and the annular protrusion 106 of the cover member 40 pass through the through hole 92, and the protrusion 104 is a bush. 74 is fitted into the annular convex portion 84. As a result, the rotor 46 is pivotally supported by the cover member 40 reliably and rotatably without causing an axis deviation, and the rotation center of the rotor 46 matches the center of the through hole 92 of the substrate 50.
[0036]
Further, as described above, since the diameter of the through-hole 92 of the substrate 50 and the diameter of the annular convex portion 106 formed in the cover member 40 are substantially equal, the outer peripheral wall portion of the annular convex portion 106 of the cover member 40 is formed on the substrate 50. The through hole 92 is fitted with no gap. By this fitting, the substrate 50 is surely positioned and fixed, and the center axes of the resistors 48 a and 48 b coincide with the rotation center of the rotor 46.
[0037]
Further, the annular convex portion 84 of the bush 74 is inserted between the protruding portion 104 and the annular convex portion 106 of the cover member 40. As a result, the side wall portion of the protruding portion 104 of the cover member 40 and the inner peripheral wall of the annular convex portion 84 of the bush 74, that is, the sliding contact portion between the bush 74 and the cover member 40, It is sealed by 40 annular convex portions 106.
[0038]
The cover member 40 placed in this way is joined to the housing 38 by heat fitting, and a thermosetting resin 110 is filled between the cover member placement portion 68 of the housing 38 and the cover member 40. Thereby, the opening 36 of the housing 38 is sealed by the cover member 40.
[0039]
The throttle opening sensor 30 according to the present embodiment is basically configured as described above. Next, the function and effect will be described.
[0040]
When the throttle valve of an automobile or the like is opened and the shaft of the throttle valve is rotationally displaced, the rotational portion 80 and the bush 74 (the entire rotor 46) of the throttle opening sensor 30 are integrally rotated following this. The Therefore, the brushes 86a and 86b slide on the surfaces of the resistors 48a and 48b, respectively. As a result, the resistance value between the three terminal boards 60a to 60c changes according to the amount of rotation of the rotor 46. By converting the change in the resistance value, the opening of the throttle valve is detected. Of course, the resistance value is measured via an external terminal inserted into the external terminal connection port 64 of the throttle opening sensor 30 and electrically connected to one end portions 62a to 62c of the terminal plates 60a to 60c.
[0041]
When the rotor 46 rotates, the annular protrusion 84 of the bush 74 and the protrusion 104 of the cover member 40 that pivotally supports the annular protrusion 84 are in sliding contact with each other. For this reason, there is no denying the possibility that both wear and wear powder is generated. However, since both sliding contact portions are sealed by the annular convex portion 106 of the cover member 40, when wear powder is generated, the wear powder is captured by the annular convex portion 106 of the cover member 40. For this reason, wear powder does not scatter in the sensor case 42. Therefore, for example, there is no problem that wear powder adheres to the surfaces of the resistors 48a and 48b and the accurate opening of the throttle valve cannot be detected.
[0042]
Further, the generated wear powder is accommodated in the space 102 provided in the protruding portion 104 of the cover member 40. For this reason, scattering of wear powder can be further suppressed.
[0043]
In addition, since the annular convex part 84 of the bush 74 and the annular convex part 106 of the cover member 40 are spaced apart from each other by a predetermined distance, they are not worn and wear powder is not generated.
[0044]
Further, since the substrate 50 is positioned and fixed by being supported by the annular convex portion 106 of the cover member 40, the rotation center of the rotor 46 and the central axes of the resistors 48a and 48b are matched. For this reason, since the brushes 86a and 86b are surely brought into sliding contact with the surfaces of the resistors 48a and 48b on the substrate 50, the opening degree of the throttle valve can be accurately detected.
[0045]
Then, when the throttle valve is closed and the shaft of the throttle valve is rotationally displaced and returned to the original position, the rotor 46 has the coil spring 44 in which the hook 72 is engaged with the key groove 78 of the horizontal end surface 76 of the bush 74. Return to the original position by energizing the bullet.
[0046]
Thus, in the throttle opening sensor 30 according to the present embodiment, the sliding between the rotor 46 and the cover member 40 is performed by the annular convex portion 84 formed on the bush 74 and the annular convex portion 106 formed on the cover member 40. Since the contact portion is sealed and the substrate 50 is positioned and fixed by being supported by the annular convex portion 106 of the cover member 40, the opening degree of the throttle valve can be accurately detected.
[0047]
【The invention's effect】
As described above, according to the throttle opening sensor according to the present invention, the sliding contact portion between the rotor and the cover member is sealed by the annular convex portion formed on the rotor and the annular convex portion formed on the cover member. I am doing so. For this reason, the wear powder generated at the sliding contact portion is captured. As a result, the effect that the abrasion powder can be prevented from scattering in the sensor case is achieved.
[0048]
In addition, since the wear powder storage portion that stores the generated wear powder is provided, scattering of the wear powder can be further suppressed.
[0049]
Further, since the substrate is positioned and fixed by supporting the substrate with the annular convex portion of the cover member, the contact is surely brought into sliding contact with the resistor formed on the substrate at a predetermined position. For this reason, the opening degree of the throttle valve can be accurately detected.
[Brief description of the drawings]
FIG. 1 is a schematic exploded perspective view of a throttle opening sensor according to the present embodiment.
FIG. 2 is a schematic longitudinal sectional view of a throttle opening sensor according to the present embodiment.
FIG. 3 is a schematic longitudinal sectional view of a throttle opening sensor according to the prior art.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1, 30 ... Throttle opening sensor 2, 32 ... Rotor insertion hole 3, 38 ... Housing 4, 40 ... Cover member 5, 42 ... Sensor case 6, 46 ... Rotor 7, 80 ... Turning part 8, 74 ... Bush 9 , 76 ... Horizontal end faces 10, 84, 106 ... Annular projections 12a, 12b, 86a, 86b ... Brushes 13, 50 ... Substrates 14a, 14b, 48a, 48b ... Resistors 15a-15c, 60a-60c ... Terminal board 18, 92 ... Through-hole 19, 104 ... Projection part 102 ... Space (wear powder accommodating part)

Claims (1)

A housing having a rotor insertion hole;
A rotor inserted into the rotor insertion hole and rotated in accordance with the rotational displacement of the throttle valve shaft, and having a first annular convex portion;
A contact fixed to the rotor;
A substrate having a through-hole and formed with a resistor to which the contact slidably contacts;
A terminal plate in contact with the resistor;
A cover member having a second annular protrusion provided at a position surrounding the sealed opening of the housing and hollow projection and projecting portion,
With
The resistor has a portion extending along the periphery of the through hole,
The substrate is positioned by fitting a second annular convex portion of the cover member into the through hole,
The protruding portion of the cover member is inserted into the first annular convex portion of the rotor passed through the through hole in a state where its center substantially coincides with the center of the through hole, and the first of the rotor The annular convex portion is surrounded by the second annular convex portion of the cover member , and the inner wall of the first annular convex portion of the rotor , which is a sliding contact portion, and the side wall of the protruding portion of the cover member are the first and the second. Sealed by the second annular projection ,
The abrasion powder generated in the sliding portion, a throttle opening sensor, characterized that you accommodated in an internal space provided in the projecting portion of the cover member.

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