JP2007240339A - Linearly moving dimension measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a linearly moving dimension measuring device capable of reducing a contact pressure of a measuring probe onto a measuring object, while maintaining a wide measuring range, reducing hysteresis by reducing deflection and backlash of the measuring probe, and improving repeat accuracy. <P>SOLUTION: This direct-acting dimension measuring device is equipped with arm members 8a, 8b to which measuring probes 7a, 7b are fixed; slide shaft members 9a, 9b extending in the siding direction of the measuring probes 7a, 7b; bearings 10a-10d having a larger separation dimension t2 than the length t1 from the contact position of a work W to the slide shaft members 9a, 9b, for supporting slidably both ends of the slide shaft members 9a, 9b; and pressing means 11a, 11b for pressing the arm members 8a, 8b through a coil spring 12 to thereby slide them together with the slide shaft members 9a, 9b, and thereby bringing the measuring probes 7a, 7b into contact with the work W. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a direct-acting dimension measuring apparatus that measures a dimension of a desired part of a measurement object by bringing the measurement probe into contact with the measurement object while sliding on a straight line.

  In general, there are two types of dimension measuring devices that measure the diameter of the object to be measured, such as contact type and non-contact type, but contact type is usually more environmentally resistant than non-contact type. It is excellent and has high reliability in dimensional measurement because there are few erroneous measurements even on an object to be measured to which an oil film adheres. Such contact-type dimension measuring devices are further roughly classified into a rotary support type that moves the measurement probe in an arc shape and a linear movement type that moves the measurement probe on a straight line.

  Of these, the rotary bearing type has a smaller driving resistance of the measurement probe than the direct acting type and can be driven with a low operating load. The dimensional change and the operation of the measurement probe do not have a linear proportional relationship, and it is difficult to cope with a wide measurement range. However, in the measurement process that needs to be compatible with a wide range of measurement, a dimension measuring device of the linear motion support system (linear motion dimension measuring device) has been used in the past, especially in order to apply to the automated process, A device capable of measuring a dimension by contacting a measurement object while sliding a measurement probe on a straight line by driving a drive source such as a motor has been used. In addition, since this prior art does not relate to the literature known invention, there is no prior art document information to be described.

  However, although the above-mentioned conventional linear motion type dimension measuring apparatus can cope with a wide range of measurement, since the driving resistance of the measurement probe is larger than that of the rotation support type, the object to be measured of the measurement probe is There has been a problem that the contact pressure against becomes large. Therefore, if the contact pressure on the object to be measured is large, the measurement error due to the bending of the measurement probe or the minute depression formed on the object to be measured becomes large, and the reliability of the apparatus is lowered. was there.

  Further, in many linear motion support systems, an arm member with a measurement probe attached to the tip, a slide shaft such as a ball screw extending in the sliding direction of the measurement probe, and an arm member on the slide shaft It is common to have a bearing that is slidably connected and supported. However, in order to ensure a wide measurement range, the arm member is set to be relatively long, and the slide shaft is moved from the contact position of the measurement probe. It is necessary to increase the dimension up to the shaft center. In that case, since the play caused by the clearance in the bearing (clearance required between the base end side of the arm member for sliding) is transmitted to the measurement probe via the relatively long arm member, When amplified, it becomes large and causes measurement errors.

  Furthermore, a moment is generated in the arm member due to the operation driving load for driving the measurement probe and the reaction force from the contact portion when the measurement probe contacts the object to be measured. There is a tendency for the deflection on the attached side) to increase, and in combination with the above-mentioned play, this causes a complicated hysteresis in the sliding of the measurement probe. In this case, there is a problem that the repetition accuracy of the entire dimension measuring apparatus is lowered.

  The present invention has been made in view of such circumstances, and reduces the contact pressure of the measurement probe against the object to be measured while maintaining a wide measurement range, and reduces the deflection and backlash of the measurement probe to reduce hysteresis. It is another object of the present invention to provide a direct-acting dimension measuring device that can improve the repeatability.

  According to the first aspect of the present invention, there is provided a linear motion type dimension measuring apparatus for measuring a dimension of a desired part of the measurement object by sliding the measurement probe on a straight line and contacting the measurement object. From the contact position between the arm member to which the probe is fixed, the slide shaft member that is fixed to the base end side of the arm member and whose axis extends in the sliding direction of the measurement probe, and the object to be measured of the measurement probe A pair of bearings that support both ends of the slide shaft member while having a separation dimension larger than the length to the shaft center of the slide shaft member, and slidably support the slide shaft member in the axial direction; A pressing unit that presses the arm member through a predetermined elastic member to slide the arm member together with the slide shaft member and to bring the measurement probe into contact with the object to be measured; And wherein the door.

  According to a second aspect of the present invention, the linear dimension measuring apparatus according to the first aspect, wherein the arm member is provided in a pair of left and right, and the other is a slide shaft member fixed to the base end side of one arm member. The base end side of the arm member is connected, and a support member that supports the other arm member while allowing the slide shaft member to slide is formed at the connecting portion.

  According to a third aspect of the present invention, in the linear motion type dimension measuring apparatus according to the first or second aspect of the present invention, the linear movement type dimension measuring apparatus includes a detection unit that detects the approach of the pressing unit to the arm member, and the detection unit detects the approach. Based on this, the pressing operation by the pressing means is stopped.

  According to the first aspect of the present invention, the pressing means can press the arm member via the predetermined elastic member to bring the measuring probe into contact with the object to be measured, so that the measuring probe can be measured while maintaining a wide measuring range. The contact pressure with respect to an object can be reduced. At the same time, bearings that support both ends of the slide shaft member while being slidable are arranged with a separation dimension larger than the length from the contact position of the measurement probe to the object to be measured to the axis of the slide shaft member. Therefore, it is possible to reduce the deflection and backlash of the measurement probe to reduce the hysteresis and improve the repeatability.

  According to the invention of claim 2, the base end side of the other arm member is connected to the slide shaft member fixed to the base end side of one arm member, and the slide portion of the slide shaft member is allowed to slide at the connecting portion. However, since the support member that supports the other arm member is formed, the operation of the arm member in the rotation direction relative to the slide shaft member can be regulated by the support member, and the both arm members are more reliably supported. In addition, the entire linear motion type dimension measuring apparatus can be reduced in size as compared with the support member formed as a member separate from the slide shaft member.

  According to the invention of claim 3, the measuring probe is provided with the detecting means for detecting the approach of the pressing means to the arm member, and the pressing operation by the pressing means is stopped based on the detection by the detecting means. It is possible to accurately grasp the point in time when it is touched and to immediately stop the pressing by the pressing means.

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.
The linear motion type dimension measuring apparatus according to this embodiment measures a dimension (specifically, an outer diameter) of a desired part of the measurement object by bringing the measurement probe into contact with the measurement object while sliding on a straight line. As shown in FIGS. 1 and 2, the base part 1, the main body part 6, the lower surface fixing part 2 disposed on the base part 1, and the main body part 6 can be moved up and down. The movable portion 3 is mainly composed of a movable portion 3, an upper surface fixing portion 4 disposed on the movable portion 3, and a measuring portion 5.

  The lower surface fixing portion 2 and the upper surface fixing portion 4 are respectively formed with protrusions 2a and 4a that can come into contact with the lower surface and the upper surface of the workpiece W as an object to be measured. Then, the movable part 3 is lowered in a state where the work W is placed on the protrusion 2a of the lower surface fixing part 2, thereby bringing the protrusion 4a of the upper surface fixing part 4 into contact with the upper surface of the work W. Is configured to be clamped from above and below.

  The measuring unit 5 is a part for measuring the outer diameter of the workpiece W fixed as described above. As shown in FIGS. 3 and 4, the pair of left and right arm members 8a and 8b and the pair of upper and lower slide shaft members. 9a and 9b, bearings 10a to 10d, pressing means 11a and 11b, a coil spring 12 as an elastic member, a ball screw 13 that can be rotated by a motor M, and a pair of linear gauges S1 and S2 (see FIG. 1) And is composed mainly of.

  The arm members 8a and 8b can be moved close to or away from each other by linearly sliding in the left-right direction in the figure while the measurement probes 7a and 7b are fixed to the tips, respectively. The tip of the actuator S2a of the linear gauge S2 is in contact with the inner surface of the member 8a), and the operator S1a of the linear gauge S1 is attached to the inner surface of the right arm member 8b (hereinafter referred to as the right arm member 8b). It is comprised so that a front-end | tip may contact | abut. Thus, the separation dimension of the measurement probes 7a and 7b can be detected based on the measurement values of the linear gauges S1 and S2.

  Further, the base end side of the left arm member 8a is fixed to the lower slide shaft member 9b (hereinafter referred to as the second slide shaft member 9b) via the fixing member 17, and the upper slide shaft member 9a (hereinafter referred to as the first slide shaft member 9a) is slidably connected via a support member 15. On the other hand, the base end side of the right arm member 8b is fixed to the first slide shaft member 9a via the fixing member 14, and is slidable to the second slide shaft member 9b via the support member 16. It is connected.

  The first slide shaft member 9a and the second slide shaft member 9b are composed of long members whose shaft centers extend in the sliding direction of the measurement probes 7a and 7b (left and right in the figure), and both ends are bearings 10a. 10b, 10c, and 10d, and each is slidable in the left-right direction. In other words, the bearings 10a to 10d are configured to be able to support the first slide shaft member 9a and the second slide shaft member 9b so as to be slidable in the axial direction. The first slide shaft member 9a is integrated with the left arm member 8a having the measurement probe 7a and slidable in the left-right direction together with the left arm member 8a. The first slide shaft member 9a has the right arm member 8b having the measurement probe 7b. And is slidable in the left-right direction together with the right arm member 8b.

  Here, as shown in FIG. 5, the bearings 10a, 7b are longer than the length t1 from the contact position of the measurement probes 7a, 7b with the workpiece W to the axis of the first slide shaft member 9a and the second slide shaft member 9b. The separation dimension t2 of 10b (same for 10c and 10d) is set to be larger. Thereby, the influence with respect to the measurement probes 7a and 7b generated by the first slide shaft member 9a and the second slide shaft member 9b supported by the bearings 10a to 10d can be reduced as much as possible. , 7b can be reduced and the hysteresis can be reduced to improve the repeatability.

  However, even if the second slide shaft member 9b slides with the left arm member 8a, the support member 16 supports the base end side of the right arm member 8b while allowing the slide, while the first slide shaft member 9a. Even if it slides with the right arm member 8b, the support member 15 is configured to support the base end side of the left arm member 8a while allowing the sliding. That is, the base end side of the other arm member is connected to a slide shaft member fixed to the base end side of one arm member, and the other arm member is allowed to slide while allowing the slide shaft member to slide. The supporting member to support is formed.

  The pressing means 11a and 11b press the left arm member 8a and the right arm member 8b via the coil springs 12 and 12, respectively, so that the left arm member 8a and the right arm member 8b are moved to the second slide shaft member 9b and the first The probe is slid together with the slide shaft member 9a to bring the measurement probes 7a and 7b close to each other. The pressing means 11a and 11b are connected to the ball screw 13 at their base ends, and can move to the left and right as the rotational driving force of the motor M is transmitted. In the process of approaching each other, the left arm member 8a and the right arm The member 8b is pressed so that they can be brought close to each other.

  The coil spring 12 is disposed on the outer periphery of the bolt B inserted from the pressing means 11a, 11b to the arm members 8a, 8b, and is interposed between the pressing means 11a, 11b and the arm members 8a, 8b. It is a thing. The bolt B has a distal end fixed to the arm members 8a and 8b and a base head located on the pressing means 11a and 11b. The bolt B is provided on the arm members 8a and 8b of the pressing means 11a and 11b. While further separation from the state of FIG. 3 is restricted, proximity is allowed and pressing via the coil spring 12 is possible.

  Therefore, the measurement probes 7a and 7b can be brought into contact with the side surface of the workpiece W by the left pressing means 11a and the right pressing means 11b pressing the left arm member 8a and the right arm member 8b via the coil spring 12 as an elastic member. Therefore, the measurement probes 7a and 7b can be brought into extremely soft contact with the workpiece W by the elasticity of the coil spring 12, and the contact pressure of the measurement probes 7a and 7b with respect to the workpiece W can be reduced while maintaining a wide measurement range. be able to.

  The ball screw 13 is connected to the output shaft of the motor M and is rotated by driving the motor M. The ball screw 13 is rotated by the drive of the motor M, and the proximal end of the left pressing means 11a (hereinafter referred to as the left pressing means 11a) and the right pressing means 11b ( (Hereinafter referred to as the right pressing means 11b), and the outer peripheral screws are formed oppositely at the connecting portion with the left pressing means 11a and the connecting portion with the right pressing means 11b. As a result, if the motor M is driven to rotate forward, the left pressing means 11a and the right pressing means 11b move in the approaching direction, and if the motor M is driven reversely, the left pressing means 11a and the right pressing means 11b. And move away from each other.

  Further, a photo sensor 19 is formed on the left pressing means 11a, and an extending portion 18 is extended from the left arm member 8a toward the left pressing means 11a. The photo sensor 19 and the extending portion 18 constitute detection means in the present invention. When the left pressing means 11a is close to the left arm member 8a, light transmission and reception by the photo sensor 19 is blocked, and the proximity is prevented. It is configured so that it can be detected.

  Specifically, in the process in which the left pressing means 11a presses and slides the left arm member 8a via the coil spring 12, when the measurement probe 7a contacts the outer peripheral surface of the workpiece W, the left arm member 8a is stationary. Then, the left pressing means 11a approaches the coil spring 12 while compressing the coil spring 12, so that the extending portion 18 changes from the state of FIG. 7 to the state of FIG. 8, and the light receiving element 19b receives the light h emitted from the light emitting element 19a. No light is received.

  The detection signal for blocking the light h is sent to the drive control unit of the motor M, and the motor M is stopped instantaneously. Similar detection means are formed on the right pressing means 11b and the right arm member 8b so that the proximity of the right pressing means 11b to the right arm member 8b can be detected. As a result, it is possible to accurately grasp the point in time when the measurement probes 7a and 7b contact the workpiece W and to immediately stop the pressing by the left pressing means 11a and the right pressing means 11b, so that the workpieces of the measuring probes 7a and 7b can be stopped. Soft contact with W can be maintained.

Next, the operation of the linear motion type dimension measuring apparatus will be described.
First, as shown in FIGS. 3 and 4, the workpiece W is sandwiched and fixed between the protrusions 2a and 4a in a state where the measurement probes 7a and 7b are sufficiently separated from each other. When the motor M is driven to rotate forward in such a state, the left pressing means 11a moves in the right direction in the figure, and the right pressing means 11b moves in the left direction in the figure, so that the left arm member 8a, The right arm member 8b is pressed.

  These left arm members 8a are slid to the right together with the second slide shaft member 9b by being pressed by the left pressing means 11a, and their base ends are slid by the support member 15 to the right arm member 8b. The first slide shaft member 9a is supported while being allowed to slide (not interlocked with the first slide shaft member 9a), while the right arm member 8b is pressed by the right pressing means 11b, so that the first While sliding with the slide shaft member 9a, the base end of the support member 16 allows the second slide shaft member 9b to slide as the left member 8a slides (not linked with the second slide shaft member 9b). However, it is supported.

  As a result, the support members 15 and 16 can restrict the rotation of the left arm member 8a and the right arm member 8b in the rotational direction relative to the first slide shaft members 9a and 9b, thereby further supporting both the arm members 8a and 8b. As a result, the entire linear motion type dimension measuring apparatus can be reduced in size as compared with a structure in which the support members 15 and 16 are formed separately from the slide shaft members 9a and 9b. In other words, the first slide member 9a can serve both as a slide portion of the left arm member 8a and a function as a rotation restriction of the right arm member 8b, and the second slide member 9b The function as the slide portion of the arm member 8b and the function as the rotation restriction of the left arm member 8a can be combined.

  However, the actuator S2a of the linear gauge S2 is displaced with the sliding of the left arm member 8a, while the actuator S1a of the linear gauge S1 is displaced with the sliding of the right arm member 8b, and these displacements can be measured. It has become. Accordingly, when the right arm member 8a and the left arm member 8b are pressed and slid and approach each other, the measurement probes 7a and 7b come into contact with both side surfaces of the workpiece W as shown in FIGS. Detecting means comprising the extending portion 18 and the photosensor 19 detects and stops the motor M.

  That is, when the measurement probe 7a, 7b comes into contact with the workpiece W, the left arm member 8a and the right arm member 8b come to rest, while the left pressing member 11a and the right pressing member 11b compress the coil spring 12 and the left arm member 8a and As shown in FIG. 8, the extending portion 18 is interposed between the light emitting element 19 a and the light receiving element 19 b in the photosensor 19 as it approaches the right arm member 8 b.

  If the light receiving element 19b does not receive the light h emitted from the light emitting element 19a through the extension portion 18, it can be determined that the measurement probes 7a and 7b are in contact with the workpiece W. The driving is stopped, and the pressing operation by the left pressing means 11a and the right pressing means 11b is stopped. Therefore, although the measurement probes 7a and 7b are in contact with the workpiece W, the pressing by the pressing means 11a and 11b is continued, and it can be reliably avoided that the contact pressure becomes excessive.

  Thus, the displacement of the left arm member 8a and the right arm member 8b at the time when the motor M stops is measured by the linear gauges S1 and S2, and based on this, the dimension between the contact points of the workpiece W of each measurement probe 7a, 7b is grasped. Then, the outer diameter of the workpiece W can be detected. After detecting the outer diameter, when the motor M is driven in reverse and the pressing means 11a and 11b are separated, the arm members 8a and 8b are also separated by the bolt B, and returned to the initial position to be in a standby state. It is preferable to provide a sensor (not shown) for detecting that the pressing means 11a and 11b have reached the initial position, and to stop the motor M when the initial position is reached.

  According to this embodiment, the pressing means 11a, 11b can press the arm members 8a, 8b via the coil spring 12 to bring the measurement probes 7a, 7b into contact with the workpiece W, and the slide shaft members 9a, 9b The bearings 10a to 10d that support both ends while being slidable have a separation dimension t2 larger than the length t1 from the contact position of the measurement probes 7a and 7b to the workpiece W to the axis of the slide shaft members 9a and 9b. Therefore, the contact pressure of the measurement probes 7a and 7b against the workpiece W can be reduced while maintaining a wide measurement range, and at the same time, the bending and backlash of the measurement probes 7a and 7b are reduced to reduce hysteresis. The repetition accuracy can be improved.

  Although the present embodiment has been described above, the present invention is not limited to this. For example, the measurement probes 7a and 7b are in contact with the workpiece W instead of the detection means including the extending portion 18 and the photosensor 19. It is good also as other detection means (it may be a contact type or a non-contact type) which can detect this. The pressing means 11a and 11b are driven by the motor M and the ball screw 13, but other general-purpose driving mechanisms may be used.

  Further, in the present embodiment, the pressing means 11a and 11b press the arm members 8a and 8b via the coil spring, but instead of the coil spring, other elastic members (such as elastic rubber or resin). ). In the present embodiment, the workpiece W is fixed in the vertical direction with respect to the floor surface, and the measurement by the measuring unit 5 is performed. However, the workpiece W may be fixed in the horizontal direction. .

  The measurement probe can be brought into contact with the object to be measured by pressing the arm member via the elastic member, and a bearing that supports both ends of the slide shaft member while being slidable is the object to be measured of the measurement probe. As long as it is a direct-acting dimensional measuring device that is arranged with a separation dimension larger than the length from the contact position to the axis of the slide shaft member, one with a different external shape or with other functions added The present invention can also be applied.

The whole front view of the direct acting type dimension measuring device concerning the embodiment of the present invention. The left side view of the linear motion type dimension measuring device, partially broken It is a top view which shows the measurement part in the linear motion type dimension measuring apparatus, Comprising: The schematic diagram which shows the state which the measurement probe separated The front view which shows the measurement part, and is the schematic diagram which shows the state which the measurement probe separated It is a top view which shows the same measurement part, and is a schematic diagram which shows the state which the measurement probe contacted the to-be-measured object It is a front view which shows the measurement part, and is a schematic diagram which shows the state which the measurement probe contacted the to-be-measured object The figure which shows the detection means in the direct acting type dimension measuring apparatus (VII section enlarged view in FIG. 3), and is a schematic diagram showing a state where the pressing member is not approaching the arm member The figure which shows the detection means in the same linear type | mold dimension measuring apparatus (VIII part enlarged view in FIG. 5), Comprising: The schematic diagram which shows the state which the pressing member has not approached with respect to the arm member

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stand part 2 Lower surface fixing part 3 Movable part 4 Upper surface fixing part 5 Measuring part 6 Main body part 7a, 7b Measurement probe 8a, 8b Arm member 9a, 9b Slide shaft member 10a-10d Bearing 11a, 11b Pressing means 12 Coil spring (elasticity) Element)
13 Ball screw 14, 17 Fixing member 15, 16 Support member 18 Extension part (detection means)
19 Photosensor (detection means)
S1, S2 Linear gauge M Motor W Workpiece (Measurement object)

Claims (3)

In a direct-acting dimension measuring device that measures a dimension of a desired part of the measurement object by contacting the measurement object while sliding the measurement probe on a straight line,
An arm member having the measurement probe fixed to the tip;
A slide shaft member fixed to the base end side of the arm member and having an axial center extending in the sliding direction of the measurement probe;
While supporting both ends of the slide shaft member while having a separation dimension larger than the length from the contact position of the measurement probe to the object to be measured to the axis of the slide shaft member, the slide shaft member is supported in the axial direction. A pair of bearings slidably supported on the
A pressing means capable of sliding the arm member together with the slide shaft member by pressing the arm member via a predetermined elastic member, and bringing the measurement probe into contact with the object to be measured;
A linear dimension measuring device characterized by comprising:   The arm members are arranged in a pair on the left and right sides, and the base end side of the other arm member is connected to the slide shaft member fixed to the base end side of the one arm member, and the connecting portion includes the slide shaft member. 2. The linear motion type dimension measuring apparatus according to claim 1, wherein a support member that supports the other arm member while allowing sliding is formed.   3. The direct operation according to claim 1, further comprising detecting means for detecting the approach of the pressing means to the arm member, and stopping the pressing operation by the pressing means based on detection by the detecting means. Dynamic dimension measuring device.

Images