JPH06307819A - Automatic measuring device for inter-wire gap and falling angle of coil spring - Google Patents

Abstract

PURPOSE:To prevent increase in the spot diameter of a beam and drop of the measuring accuracy due to turn-around by using a laser beam as a medium for measuring. CONSTITUTION:One set of prisms 11, 12 are furnished inside of a coil layer of a coil spring 8, and correspondingly on the outside of the coil layer, laser beam projecting apparatus 13A, 13B and receiving apparatus 14A, 14B are furnished in such a way as mating with the prisms 11, 12. One end of the coil spring 8 is grasped by a chuck 1, and it is rotated intermittently by an indexing rotational mechanism 3, and meantime the prisms 11, 12 and the laser beam projecting and receiving apparatuses 13A, 13B, 14A, 14B are moved at a constant speed in the axial direction of the coil spring 8 by a constant speed feeding mechanism 15 while they are held in the specified relative positions. On the way of this constant speed movement, laser beams are cast off from the projecting apparatus 13A, 13B, reflected by the reflex surfaces of the prisms 11, 12, and put incident to the receiving apparatus 14A, 14B, and thereby the sensing signals of the inter-wire gap and wire falling angle are sent to a computational control part 5 at certain time intervals.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic measuring device for wire gaps and tilt angles of coil springs.
When the cross-sectional shape of the wire forming the spiral spring is a non-circular shape such as a closed loop of a clothoid curve or an elliptical shape, an automatic measuring means for accurately and continuously measuring the inter-wire gap of the wire and the tilt angle of the coil wire. Is provided.

[0002]

2. Description of the Related Art Conventionally, a wire gap of a coil spring is manually measured by using a gap gauge or the like. However, such manual measurement is inefficient, and there is a problem in measurement operation in maintaining the measurement accuracy at a high level.

In order to solve such a problem, the applicant of the present invention previously disclosed in Japanese Patent Application No. 63-52289 an automatic measuring device using a photoelectric sensor as a measuring means between the wire gaps of a coil spring. is suggesting. A schematic structure and an operating procedure of the automatic measuring device for the line gap of the coil spring will be described as a prior art of the present invention with reference to FIG.

As shown in FIG. 3A, an automatic measuring device (10) for measuring the inter-line gap (G) of a coil spring (8) according to the present invention, as shown in FIG. 1) and
The winding spring (8), which is gripped by the chuck (1) and is rotatably supported, is configured to be insertable across the coil from the other end, and photoelectric sensors (6) and (7) are provided opposite to the respective tips. A bifurcating fork-shaped measuring head (2), an indexing rotating mechanism (3) for intermittently rotating the chuck around the central axis of the winding spring (8), and a winding spring (8) for the relative head (2). Constant speed feed mechanism (4) consisting of a support bracket (4a), a guide rod (4b), a pulse motor (4c), and a feed screw (4d) for constant speed movement in a direction parallel to the central axis of the Under the synchronous control of the mechanism (3) and the constant speed feed mechanism (4), the feed rate of the constant speed feed mechanism (4) and the photoelectric sensor (6) are set for each indexing angle position along the circumferential direction of the coil spring (8). ) From the detection signal of (7), determine the wire gap (G) of the coil spring (8). It is constituted by the operation control means for output (5).

While the winding spring (8) whose one end is gripped by the chuck (1) is intermittently rotated by a predetermined angle by the indexing rotation mechanism (3), from the other end of the winding spring, the constant speed feed mechanism (4). Measuring head using the feeding operation by (2)
Insert and go. The coil of the coil spring (8) traverses the light projecting and receiving path formed between the photoelectric sensors (6) and (7), so that the wire rod and the actual portion of the wire material forming the coil spring (8) and the inter-wire gap (G). The size of the detection signal changes at the formation portion of, that is, the non-existing portion of the wire. The length (G ₀ ) of this detection signal is arithmetically processed by the arithmetic control means (5) with reference to the moving speed of the measuring head (2) as shown in FIG. The line gap (G) is required. The arithmetic control means (5) synchronously controls the indexing rotation mechanism (3) and the constant speed feed mechanism (4) to control the indexing angular position along the circumferential direction of the coil spring (8). Based on the feed rate of the rapid feed mechanism (4) and the gap detection signal (G ₀ ) sent from the photoelectric sensors (6) (7), the coil spring (8)
It is provided for calculating the inter-line gap (G), and is composed of a computer (5a) and an amplifier (5b).

Automatic measuring device (10) for the line gap (G)
By using, the decrease in measurement accuracy and the measurement labor, which have been problems when a gap gauge or the like is used, are considerably suppressed.

[0007]

When the line gap (G) of the coil spring (8) is measured using the above-mentioned conventional automatic measuring device (10), the photoelectric projector (6) and the photoreceiver are used. The gap detection signal (G ₀ ) is sent to the computer (5a) by projecting a light beam between (7). When the photoelectric tube system is adopted as the light source as described above, the light beam has a slight scattering property, and therefore a part of the light beam wraps around the periphery of the spiral spring (8) which is a symmetrical object of measurement. According to the measurement results of the present inventors, the spot property of the light beam projected from the light projector (6) is set to a constant value, for example, 1 mm for the increase of the spot diameter of the light beam due to the interference or scattering of the light. In this case, when it reaches the irradiation area of the coil spring (8), it reaches 15 μm to 20 μm, and the magnitude of the detection signal of the inter-line gap (G) changes by the increase of this spot diameter, as shown in FIG. 3 (B). As indicated by the chain double-dashed line and the reference sign (Ge), an error different from the actual line gap (G) | G ₀ −
The detection signal (Ge) including Ge |
Will be sent to. As a result, it becomes quite difficult to maintain the measurement accuracy of the line gap (G). That is, when the photoelectric tube method is adopted, it is necessary to add the correction function of the error | G ₀ −Ge | to the operation control means (5) in order to improve the measurement accuracy, and the operation control circuit of the computer (5a) It will be complicated. More specifically, when the coil spring (8) is formed of a wire having a circular cross section, the error | G ₀ −Ge | is relatively easy to correct. If the cross-sectional shape is a square or a closed loop of clothoid curve, the light rays are more susceptible to interference and scattering due to the directionality of the wire rod with respect to the projection direction of the light rays. G) and the measurement of the tilt angle of the coil require complicated correction calculation. As a result, the measurement index is lowered, labor saving is hindered, and various restrictions are involved in maintaining the measurement accuracy.

[0008]

As a means for solving the above problems, the present invention provides a chuck for supporting one end of a coil spring so as to be capable of intermittent rotation, an indexing rotation mechanism which is connected to the chuck and provides intermittent rotation, and the chuck described above. A pair of prisms, which are inserted into the inside of the coil spring from the other end of the coil spring whose one end is gripped by, and which move at a constant speed along the axial direction of the coil spring while maintaining a predetermined opposing interval; A projector for projecting laser light from the outside of the coil spring through the line gap to the prism, and a receiver for receiving the laser beam whose optical axis direction is changed by the reflecting surface of the prism on the coil spring outside. A constant speed feed mechanism for moving the laser light projecting / receiving structure composed of the pair of prisms, the light projector, and the light receiver at a constant relative position in the axial direction of the coil spring, Index times The mechanism and the constant speed feed mechanism are controlled, and the winding speed is determined from the feed rate of the constant speed feed mechanism and the detection signal sent from the laser light projecting / receiving structure for each indexing angle position along the circumferential direction of the coil spring. The present invention provides an automatic measuring device for a wire gap and a tilt angle of a winding spring, which is provided with a calculation control means for calculating a wire gap and a tilt angle of the spring.

[0009]

The prisms are arranged in pairs inside the coil layer of the coil spring, and correspondingly, the projector and the receiver of the laser beam are arranged outside the coil layer of the coil spring so as to face the prism. To do. While holding one end of the coil spring with a chuck and intermittently rotating it with an indexing rotation mechanism, keep the prism and the laser light emitter / receiver at a certain relative position while using the constant speed feed mechanism to move in the axial direction of the coil spring. Move along at a constant speed. During this constant speed movement, laser light is projected from the projector, reflected by the reflecting surface of the prism, and then incident on the light receiver, thereby detecting signals for the gap between the wires and the tilt angle of the wire at a predetermined time interval. To the arithmetic control means.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A concrete example of the present invention will be described below with reference to FIGS. In the following description, the same components as those in FIG. 3 showing the prior art are designated by the same reference numerals,
Description of duplicate items is omitted.

An automatic measuring device (20) for measuring a line gap (G) and a tilt angle (θ) of a coil spring (8) includes a chuck (1) for rotatably supporting one end of the coil spring (8) in a centered state so as to be intermittently rotatable. 1)
An indexing rotation mechanism (3) connected to the chuck (1) as a power source for intermittent rotation, and the chuck (1).
A pair of prisms inserted into the inside from the other end of the spiral spring (8) whose one end is gripped, and moving at a constant speed along the axial direction of the spiral spring (8) with a predetermined facing interval. (11)
(12) and one of the prisms, for example, (11), from the outside of the coil layer of the coil spring (8) through the line gap (G).
After changing the direction of the optical axis to the axial direction of the coil spring (8) by the projector (13A) for projecting the laser light on and the obliquely upward reflecting surface (11A) of the one prism (11), and then proceeding straight,
As the light receiving means for the laser light in which the direction of the optical axis is changed again in the direction perpendicular to the axis of the coil spring (8) by the obliquely upward reflecting surface (12A) of the other prism (12), the coil spring (8) is provided. The light receiver (14A) arranged outside the coil layer, and the above-mentioned 2
The axial direction of the coil spring (8) with the laser light projecting / receiving structure comprising the prism (11) (12) and the projector (13A) and the photoreceiver (14B) set in a set at a fixed relative position. The constant speed feed mechanism (15) for constant speed movement, the indexing rotation mechanism (3) and the constant speed feed mechanism (15) are synchronously controlled to follow a preset circumferential direction of the winding spring (8). For each indexing angular position, from the feed rate of the constant velocity feed mechanism (15) and the detection signals sent from the laser beam projecting / receiving structures (13A) (11) (12) (14A), the coil spring (8) is detected. Of the wire gap (G) and the calculation control means (5) for calculating the inclination angle (θ) of the wire with respect to the axis of the coil spring (8).

The light emitter (13A) and the light receiver (14A) are arranged outside the coil layer of the coil spring (8) in pairs with their optical axes parallel to each other.

In the above-mentioned embodiment, the reflecting surface (11) facing obliquely upward is provided between the first light projector (13A) and the first light receiver (14A).
A) A pair of prisms (11) (12) with (12A)
Although an automatic measurement system for the inter-line gap (G) is configured by interposing, a more preferable modified example is shown in FIG.
As shown in the enlarged view of (A), the second light projector has a coaxial arrangement in which the direction of the optical axis is aligned with that of the first light projector (13A) with a predetermined space above and below the coil spring (8). (13B) is installed in parallel, and the second optical receiver (14B) is installed in parallel with the first optical receiver (14A) in a coaxial arrangement in which the directions of the optical axes match.
Correspondingly, the obliquely downward reflecting surface (11B) of the first prism (11) and the obliquely downward reflecting surface (12B) of the second prism (12) are aligned on the laser light projection path. It is also possible to configure an automatic measurement system. According to this modification, the laser beam is projected once and the line gap (G) and the inclination angle (θ) of the wire rod are set at two points on the circumference of the coil spring (8) having a phase difference of 180 °. Is measured, the first floodlight (13
Compared to the case where only A) and the second light receiver (14A) are used, the number of measurements per revolution of the coil spring (8) is doubled, and it becomes easier to maintain the measurement accuracy.

The indexing rotation mechanism (3) shown in FIG.
A drive device having an indexing function for intermittently rotating the chuck (1) around the central axis of the coil spring (8), which includes a mounting bracket (3B) for a stepping motor and a shaft portion (17) of the chuck (1). Coupling (3C) that rotatably supports
And pillow blocks (3D) (3E).

On the other hand, the constant speed feeding mechanism (15) is arranged so that two prisms (11) and (12) fixed to the rod (16) in pairs and facing these prisms (11) and (12). Projector (13A) opposite to the coil layer of the coil spring (8)
(13B) and the light receivers (14A) and (14B) are linear motion devices that feed the springs (8) at a constant speed along the axial direction of the coil springs (8) with the integrated structure, and are provided on the base plate (18). It is composed of a motor (15C) with a feed screw (15B) and an X table (15A) having a female screw block (15D) screwed with the feed screw (15B) fixed to the bottom.

The arithmetic control means (5) is an indexing rotation mechanism.
To control (3) and constant speed feed mechanism (15) in a synchronized state
Which is basically the same as the conventional method shown in FIG.
Are the same. That is, the winding spring (8) is split along the circumferential direction.
Constant speed feed mechanism (15) for every 1/8 rotation
Laser type light emitting and receiving structure (11) (12) (13A) (13
B) (14A) (14B) feed rate and the above laser type receiving and receiving
From the detection signal sent from the optical structure to the line between the winding springs (8)
The gap (G) is calculated, and at the same time, the width (W ₂)
And the apparent width (W₁) And
The coil layer is formed with the coil spring (8) by performing a comparison operation.
Calculate the tilt angle (θ) of the wire rod.

The operation of measuring the inter-wire gap (G) and the inclination angle (θ) of the wire by the device (20) of the present invention will be described below.

First, the chuck (1) is made to grasp one end of the coil spring (8), and the constant speed feed mechanism (15) is activated while the chuck (1) is held in the stopped state, and the prism is projected while projecting laser light. (11) (12), the light projectors (13A) (13B) and the light receivers (14A) (14B), the laser light projecting / receiving structure is moved at a constant speed in the axial direction of the coil spring (8). As a result, the coil spring (8) is interposed between the prism (11) and (12) between the laser light projector (13A) and the light receiver (14A) and between the laser projector (13B) and the light receiver (14B). The measurement operation of the line gap (G) and the tilt angle (θ) is performed. That is,
By projecting a laser beam, an ON-OFF signal proportional to the wire diameter of the wire and the gap (G) between the wires is detected, and this detection signal is passed through an amplifier (5b) to a computer (5).
Send to a). At the same time, the moving amount of the laser light projecting / receiving structure is continuously sent from the constant speed sending mechanism (15) to the computer (5a). The line gap (G) of the coil spring (8) and the inclination angle (θ) of the wire rod are calculated from the ON-OFF signal and the feed speed of the light emitting / receiving structure.

With respect to one coil spring (8), the above-described measurement operation is repeated for each predetermined rotation phase angle by utilizing the rotation indexing operation of the indexing rotation mechanism (3).

The chuck (1) has a coil spring (8)
For example, it is gripped by a three-point support claw, and the entire length in the axial direction of the winding spring (8) excluding the gripping position by this hole is formed in the working area of the light emitting and receiving structure.

By using the device (20) of the present invention, various windings having different coil shapes and different cross-sectional shapes of wire rods can be used, from the winding springs (8) having an equal pitch to the winding springs (8) having an unequal pitch. The clearance (G) between the wires and the inclination angle (θ) of the wire are automatically measured for the spring. Prior to the measurement, the design value of the spiral spring (8) is input and placed in the memory of the computer (5a) of the arithmetic control means (5), the design value and the measured value are compared, and the comparison result is graphed. Alternatively, it is displayed as a numerical value and a pass / fail judgment is made.

In the above embodiment, the prism has been described as having a triangular prism shape, but if the prism is a triangular pyramid having a square bottom surface, the simultaneous measurement becomes four points, and the measurement accuracy and the measurement accuracy can be further improved.

[0023]

The use of a laser beam as a measuring medium for the inter-line gap (G) and the tilt angle (θ) of the wire material forming the coil spring (8) allows the use of a photoelectric light-emitter / receiver. It is possible to effectively avoid the problem of a decrease in measurement accuracy due to an increase in the spot diameter of the light beam and a wraparound of the light.

Two prisms (11) and (12) having upper and lower reflecting surfaces and two sets of laser light projecting / receiving devices (13A) (14A) which are vertically opposed to each other with a coil spring (8) interposed therebetween. ) And (13B) and (14B) together, the number of detection signals acquired at the same measurement position is doubled when the prism is a triangular prism, and when the prism is a triangular pyramid. Can be quadrupled, and the accuracy of the measured value is improved accordingly.

According to the present invention, it is possible to automatically measure the wire gap (G) of the coil spring (8) and the tilt angle (θ) of the wire rod which is a constituent member of the coil spring (8), which improves the measurement accuracy. Together with this, a remarkable effect can be exerted also on the omission of measurement work and the improvement of efficiency.

[Brief description of drawings]

FIG. 1 is a front view illustrating the overall structure of a device of the present invention.

FIG. 2A is a front view of a main part of the device of the present invention, and FIG. 2B is a cross-sectional view for explaining a tilt angle of a deformed wire.

FIG. 3A is a front view of a conventional device, and FIG. 3B is an orthogonal line diagram exemplarily illustrating a relationship between a moving amount of a measuring head and a detection signal.

[Explanation of Codes] 3 Indexing / Rotating Mechanism 5 Arithmetic Control Means 8 Winding Spring 11 Prism 12 Prism 13A First Projector of Laser Light 13B Second Projector of Laser Light 14A First Receiver of Laser Light 14B of Laser Light 2nd light receiver 15 Constant speed feeding mechanism 20 Automatic measuring device for gap between lines and tilt angle

Claims (2)

[Claims] 1. A chuck that supports one end of a coil spring so as to be intermittently rotatable, an indexing rotation mechanism that is connected to this chuck and that provides intermittent rotation, and a coil spring whose one end is gripped by the chuck from the other end of the coil spring. A pair of two prisms that are inserted inside the spring and move at a constant speed along the axial direction of the coil spring while maintaining a predetermined facing interval, and through the gap between the coils from the outside of the coil spring to the prism. A light projector that projects a laser beam, and a light receiver that receives the laser beam whose direction of the optical axis is changed by the reflecting surface of the prism outside the coil spring,
A constant speed feed mechanism for moving the laser light projecting / receiving structure consisting of the pair of prisms, the light projector, and the light receiver at a constant relative position in the axial direction of the coil spring while maintaining a constant relative position; Controls the feed rotation mechanism and constant speed feed mechanism,
For each indexed angle position along the circumferential direction of the coil spring, the wire gap and the tilt angle of the coil spring are calculated from the feed rate of the constant-speed feed mechanism and the detection signal sent from the laser light projecting / receiving structure. An automatic measuring device for a wire gap and a tilt angle of a coil spring, which comprises: 2. The laser light projecting / receiving structure according to claim 1 is arranged at a predetermined facing interval so as to maintain a reflection angle of 45 ° above and below or to the left and right of the axis of the coil spring. A set of two prisms, two projectors for projecting laser light from mutually opposite directions to the first prism arranged inside the coil spring, and a first projector provided opposite to the first prism. Two light receivers arranged outside the coil spring are used as light receiving means for laser beams reflected from the two prisms in mutually opposite directions. Automatic measuring device.