JPH0596579U - Leaf spring holding structure - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] When holding and fixing the proximal end of a leaf spring that is approximately T-shaped, secures an effective length of spring displacement and also makes the required swing of the leaf spring. Allow the displacement to be obtained. A leaf spring 6 is formed so as to have a generally T-shape as a whole by a base end portion 6a and a free end 6b extending from a part of the base end portion and capable of swinging displacement. The base end of the leaf spring is sandwiched and fixed between the fixed base 5 and the holding member 7 assembled and fixed to the fixed base. A U-shaped recess that allows swinging displacement at the root of the leaf spring is provided on the inner surface of the clamping base of the fixing member and the pressing member that corresponds to the root 6c at the free end extending from the base end of the leaf spring. 30, 31
To form.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a leaf spring holding structure suitable for application to, for example, an elastic spring supporting type pendulum type servo type acceleration sensor used as an in-vehicle accelerometer.

[0002]

[Prior Art]

 For example, the swing displacement of the pendulum according to the acceleration acting on the moving body is extracted as an electric signal, and this is supplied to the Toruca coil provided on the pendulum, and the magnetic force acting between the magnetic field generated in the Toruca coil and the permanent magnet. A servo-type accelerometer configured to return the pendulum to its original position is known from, for example, Japanese Utility Model Publication No. 59-26286.

That is, in a conventional servo-type accelerometer, a pendulum including an aluminum plate and a torquer coil wound around a coil bobbin integrally assembled with the aluminum plate is arranged parallel to the direction in which the acceleration acts. The pendulum is held at the free ends of a pair of elastic leaf springs hanging from the pedestal, the permanent magnets are arranged in the direction orthogonal to the surface of the aluminum plate, and the slits provided in the aluminum plate. The structure is such that an optical sensor composed of a LED and a photodiode for confirming the position of the pendulum via the is provided.

By the way, in the above-described conventional device, the aluminum plate and the torquer coil that form the pendulum are arranged at the free end of the elastic leaf spring in a state orthogonal to the extending direction of the leaf spring, and in accordance with this, the permanent coil is attached to the permanent plate. Since other members such as magnets are also arranged, there are many dead spaces, the entire size tends to be large, and assembly is troublesome.

Therefore, the present applicant previously proposed, by Japanese Patent Application No. 3-163368 and the like, an acceleration sensor which can achieve simplification of configuration, improvement of assembling property, and further miniaturization of the whole. ..

That is, as shown in FIG. 8, this acceleration sensor includes a coil bobbin 3 around which a torquer coil 2 as a pendulum 1 is wound and an aluminum plate 4 attached to the coil bobbin 3 in a vertical state. The base 5 and the base 5 are fixed to the connecting portions 3a and 3a, which are arranged in parallel with the direction in which the coil bobbins 3 are extended on both sides of the coil bobbin 3. Connect the free ends 6b, 6b of the pair of elastic leaf springs 6, 6 that are hung down and held between the holding plate 7 and the holding plate 7 which is a holding member fixed with screws or the like. The leaf springs 6 and 6 are elastically deformed in the direction in which the acceleration is applied, so that the free ends 6b and 6b and the pendulum 1 hung from the free ends 6 are allowed to perform a pendulum motion.

In such a configuration, a permanent magnet (both not shown) that cooperates with the optical sensor means for detecting the displacement of the pendulum 1 and the torquer coil 2 to generate a magnetic force is provided on both sides of the pendulum 1. The leaf springs 6 and 6 could be installed in the installation space, and the overall size could be reduced.

[0008]

[Problems to be solved by the device]

 However, in the acceleration sensor as described above, the holding structure of the elastic leaf springs 6 has a problem in practical use. That is, as is clear from FIG. 8, the above-mentioned leaf spring 6 is generally T-shaped as a whole by the base end portion 6a and the free end 6b extending from a part of the base end portion 6a and capable of swinging displacement. The base end portion 6a including the T-shaped root portion 6c of the free end 6b is sandwiched between the inner surfaces of the pedestal 5 and the pressing plate 7 which are flat surfaces. Is held.

However, in the above-described leaf spring 6, the length from the base end portion 6a to the free end 6b is long, or the assembling position of the pedestal 5 and the pressing plate 7 is deviated, so that the leaf spring 6 is held at the holding position. When a displacement or the like occurs, it is not possible to perform the swing displacement of the leaf spring 6 in a desired state, which adversely affects the movement of the leaf spring 6.

To explain this in detail, when the length up to the free end 6b is long like the former, the base end portion 6a thereof is changed to the pedestal 5 as shown in FIGS. 8 and 9 (a). If it is simply inserted between the holding plate 7 and the holding plate 7, the root 6c of the leaf spring 6 is fixed and held. Therefore, the effective length required for the swing displacement from this fixed portion to the free end 6b. Is substantially shortened and requires a certain length, it is necessary to increase the space of the spring mounting portion including the leaf spring 6. For example, in the case of an acceleration sensor, the height becomes high and This causes a problem of increasing the size.

[0012] Furthermore, the sandwiching surface between the frame 5 and the pressing plate 7 that holds the base end 6a of the leaf spring 6 sandwiches the leaf spring 6 from the free end 6b to the extension side of the leaf spring 6. Occurs, as shown in (b) and (c) of FIG. 9, the smooth and appropriate swing displacement by the leaf spring 6 is hindered, and the problem that the required spring displacement cannot be obtained occurs. It was something that was worth it.

In particular, such a problem greatly affects the sensor performance when it is necessary to detect the subtle movement of the pendulum 1 supported by the leaf springs 6 and 6. It is necessary to eliminate defects in the holding portions of the flat leaf springs 6 and 6.

The present invention has been made in view of such circumstances, and a holding portion structure for holding and fixing a leaf spring having a substantially T-shape as a whole is provided with an effective length required for displacement of the leaf spring. It is an object of the present invention to obtain a holding structure for a leaf spring that ensures the required swing displacement even if there is a problem of displacement in the holding portion of the leaf spring.

[0014]

[Means for Solving the Problems]

 In order to meet such a demand, the leaf spring holding structure according to the present invention is generally T-shaped by a base end portion and a free end extending from a part of the base end portion and capable of swinging displacement. In order to hold the base end of the leaf spring by sandwiching it between the fixing base and the holding member assembled and fixed to the fixing base, Allow the swinging displacement of the root end of the free end of the leaf spring on the inner surface of the clamp base of the holding member and the fixed base corresponding to the T-shaped root end of the free end extending from the base end of the spring. A U-shaped recess is formed.

[0015]

[Action]

 According to the present invention, the leaf spring has its base end portion sandwiched and held in a desired state between the fixed base and the pressing member, and has a T-shape extending from the base end portion to the free end. The fixing base corresponding to the root part and the inner side surface of the pressing member are notched by the U-shaped recess, and as a result, an effective length for the swing displacement of the leaf spring can be secured and the fixing base is It is possible to obtain the required oscillating displacement of the leaf spring by removing the factors that have an adverse effect on the spring displacement due to assembly errors and burrs, etc.

[0016]

【Example】

 1 to 7 show an embodiment in which the leaf spring holding structure according to the present invention is applied to a servo type acceleration sensor. In these drawings, first, the schematic configuration of the entire servo type acceleration sensor 10 will be briefly described with reference to FIGS. 4 to 7. In this embodiment, parts that are the same as or correspond to those in FIG. 8 and the like described above are assigned the same reference numerals and detailed explanations thereof are omitted.

In these figures, reference numeral 11 is a magnet plate arranged in parallel with the pendulum 1, and a pair of permanent magnets 12, 12 are provided on the inner surface of the magnet plate at predetermined intervals in the direction in which acceleration acts. It is attached in advance. The permanent magnets 12 and 12 face the left and right side surfaces of the aluminum plate 4 with a slight gap, and their magnetic poles are opposite to each other.

Reference numeral 13 denotes a spacer, and the spacer 13 is provided between the permanent magnets 12 and 12 with an LED 14 serving as a light source of an optical sensor means.

Reference numeral 15 denotes a printed circuit board which is arranged so as to face the magnet plate 11 and in which the pendulum 1 is arranged. The printed circuit board 15 is not shown in the drawing, but is used as the acceleration sensor 10. Necessary various electric circuit parts and wiring are provided. Reference numeral 16 denotes a yoke made of a magnetic plate material provided inside the printed circuit board 15. A window portion formed in a part of the yoke has a window portion formed opposite to the LED 14 and serving as a photosensor means of a two-division type. The diode 17 is provided as a light receiving element.

In FIG. 4 and the like, reference numeral 18 is a slit formed in the coil bobbin 3 and the aluminum plate 4 which compose the pendulum 1, and the photodiode 17 selectively detects the light from the LED 14 through the slit 18. A displacement detector that detects the displacement position of the pendulum 1 is configured by the electric signal generated at 1.

In the above structure, the pendulum 1 including the torquer coil 2 and the aluminum plate 4 is supported by the leaf springs 6 and 6 to oscillate in the acting direction of acceleration, that is, in the direction indicated by the arrow in FIGS. 4 and 6. It is designed to work dynamically. Further, in the acceleration sensor 10 described above, the magnet plate 11, the spacer 13, the yoke 16 and the printed circuit board 15 are laminated in a state where the pendulum 1 is incorporated in the internal space thereof and integrated by screws or the like. As a result, the entire system is miniaturized.

Further, in the acceleration sensor 10 described above, although not shown in the figure, an electric circuit including various resistors and a servo amplifier including a differential amplifier is used to control the pendulum 1 based on an electric signal obtained by the optical sensor means. A current for returning to the position is applied to the torquer coil 2, and the magnitude of acceleration can be detected by the voltage generated at both ends of the resistor connected in series with the torquer coil 2.

Here, in the acceleration sensor 10 having the above-described configuration, as shown by an imaginary line arrow in FIG. A magnetic flux loop is formed by the other permanent magnet 12 and the magnet plate 11. Then, the pendulum 1 moves in the direction of the arrow in the figure, and when acceleration is applied, the position signal generated from the optical sensor means (14, 17) changes. Then, when this signal change is supplied to the torquer coil 2 via the servo amplifier, a magnetic force acts between the current flowing through the torquer coil 2 and the magnetic field, and a force that restores the pendulum 1 acts. Therefore, the actual distance traveled by the pendulum 1 is extremely small. In addition, a voltage corresponding to the detected acceleration is generated at both ends of the resistor connected in series to the Toruca coil 2.

According to the present invention, in the servo type acceleration sensor 10 having the above-described structure, the free end which is extended from the base end portion 6a and a part of the base end portion 6a and is capable of swinging displacement. 6b and an elastic leaf spring 6 formed so as to have a substantially T-shape as a whole, and the base end 6a of the leaf spring 6 is partly screwed to a magnet plate 11 or the like. And a holding plate 7 which is disposed opposite to this and is fixed by assembling, when holding and fixing it by sandwiching it, a free end 6b extending from a base end portion 6a of the leaf spring 6 is provided. U-shaped recesses 30 and 31 that allow the swing displacement of the T-shaped root portion 6c in the leaf spring 6 are provided on the inside surface of the cradle 5 corresponding to the T-shaped root portion 6c and the holding plate 7. The feature is that the notch is formed.

In the figure, 21 is a screw for assembling the holding plate 7 which is fixed by pressing the base end portions 6a, 6a of the leaf springs 6, 6 to the frame 5, and 22 is the leaf springs 6, 6. These are screws for fastening and fixing the free ends 6b 1 and 6b 2 of the coil bobbin 3 to the connecting portions 3a and 3a provided on both sides of the coil bobbin 3.

According to such a configuration, the leaf spring 6 has its base end portion 6a sandwiched and held in a desired state between the pedestal 5 and the pressing plate 7, and at the same time, the base portion 6a is held. Inner side surfaces of the pedestal 5 and the pressing plate 7 corresponding to the T-shaped root portion 6c from the end portion 6a to the free end 6b are notched by the U-shaped recesses 30 and 31, and as a result, leaf springs are formed. It is possible to secure an effective length with respect to the swing displacement of 6, so that the space for disposing the leaf spring 6 can be reduced, and for example, the acceleration sensor 10 can be downsized, and the assembling with the pedestal 5 and the pressing plate 7 It is possible to eliminate the factors that have an adverse effect on the spring displacement due to errors and burrs, obtain the required swing displacement of the leaf spring 6, and improve the detection accuracy of the sensor. ..

Further, according to such a configuration, due to the existence of the U-shaped recesses 30 and 31 described above, the tucked portion at the base end portion 6a of the plate spring 6 by the pedestal 5 and the pressing plate 7 is formed. In addition, even if some assembly error occurs, it is possible to minimize the influence on the swing displacement of the leaf spring 6.

The present invention is not limited to the structure of the above-described embodiment, and the shape, structure, etc. of each part including the leaf spring 6, the pedestal 5 holding the leaf spring 6, the holding plate 7, etc. are appropriately modified or changed. It goes without saying that you can do it. Further, in the above-described embodiment, the case where the present invention is applied to the servo type acceleration sensor 10 has been described. However, it has a holding portion of a leaf spring whose base end is fixed and whose free end is swingably displaceable. It will be easily understood that any of them can be applied to equipment and devices in various fields.

[0029]

[Effect of the device]

 As described above, according to the leaf spring holding structure of the present invention, the base end portion and the free end extending from a part of the base end portion and swingably displaceable form a generally T-shape. In order to hold the base end of this leaf spring by sandwiching it between the fixed base and the holding member assembled and fixed to this fixed base, Allows the swinging displacement of the root of the free end of the leaf spring on the inner surface of the clamp base of the fixing base and the pressing member that corresponds to the T-shaped root of the free end extending from the base end of the leaf spring. Since the U-shaped concave portion is formed, the leaf spring can be held in a desired state between the fixed base and the pressing member, and the leaf spring can be held in spite of the simple structure. The fixing base corresponding to the T-shaped root part from the base end part to the free end, and the inner side surface part of the pressing member are U-shaped concave parts. Since the notch is formed, it is possible to secure an effective length for the swing displacement of the leaf spring, and it also has an adverse effect on spring displacement due to assembly error on the fixing base and burrs. It is possible to obtain the required oscillating displacement of the leaf spring by removing the factor, and there are various practically excellent effects.

[Brief description of drawings]

FIG. 1 is a schematic view of a pendulum and a support portion by elastic leaf springs showing an embodiment in which a leaf spring holding structure according to the present invention is applied to a servo acceleration sensor.

FIG. 2 is a schematic side view of FIG.

FIG. 3 is a view for explaining the holding structure of the present invention.
It is the schematic which expands and shows a principal part.

FIG. 4 is a front view of relevant parts for explaining a schematic configuration of the entire servo type acceleration sensor.

5 is a side sectional view showing the configuration of the main part of FIG.

FIG. 6 is a schematic plan view of a pendulum portion when FIG. 4 is viewed from the plane direction.

FIG. 7 is a schematic plan view of an elastic leaf spring portion that suspends and supports a pendulum, as seen in the plan view of FIG.

FIG. 8 is a schematic view showing a pendulum and a holding portion by an elastic leaf spring in an acceleration sensor for explaining a conventional leaf spring holding structure.

FIG. 9 shows a problem in the leaf spring holding part in FIG.
It is a schematic explanatory drawing shown in (b), (c).

[Explanation of symbols]

 1 Pendulum 2 Toruca coil 3 Coil bobbin 3a Connection part 4 Aluminum plate 5 Frame (fixed base) 6 Elastic leaf spring 6a Base end part 6b Free end 6c T-shaped root part 7 Presser plate (presser member) 10 Servo type acceleration sensor 11 Magnet plate 12 permanent magnet 13 spacer 15 printed circuit board 16 yoke 30 U-shaped recess 31 U-shaped recess

Claims (1)

[Scope of utility model registration request] 1. A leaf spring having a base end portion and a free end extending from a part of the base end portion and capable of swinging displacement so as to have a substantially T-shape as a whole. A leaf spring holding structure in which a base end portion of a leaf spring is sandwiched and held between a fixed base and a pressing member assembled and fixed to the fixed base. A U-shaped concave portion that allows swinging displacement of the root portion of the free end of the leaf spring is formed on the inner surface of the fixed portion corresponding to the root portion of the free end extending from the A holding structure for leaf springs.