Measuring head and swing fulcrum component used for measuring head

Abstract

The present disclosure provides a measuring head (80) that detects the amount of movement of a contact (85) by detecting the amount of movement of the arm member (83) that performs a seesaw-type movement by supporting an arm member (83) having a contact (85) attached to the tip thereof by means of a swing fulcrum member configured as a cross-shaped spring (10) from a cross-shaped thin plate section (10-1), the swing fulcrum member being configured as a cross-shaped thin plate section (10-1), and the swing fulcrum member being configured as a cross-shaped thin plate section (10-1), and the swing fulcrum member being configured as a cross-shaped spring (10) from a cross-shaped thin plate section (10-1). The cross spring (10) is provided with a hole in a manner of penetrating through the central part (10-3) of the cross spring (10), so that the same deformation can be obtained by a smaller load in the measurement direction, the cross spring has sufficient rigidity aiming at the torsional load in the other direction, the center of a fulcrum does not shift, and the repetition accuracy is also improved.

Description

Technical Field

[0001] The present disclosure relates to a measuring head used in a machine calibration gauge, a surface roughness profile measuring instrument, etc. assembled in a grinding machine or the like, and particularly to a measuring head using a cross-spring type swing fulcrum member and a swing fulcrum member for the measuring head. Background Art

[0002] Conventionally, a measuring head that moves an arm having a contact at its tip in the vertical direction according to the lever principle has been widely used. Such a measuring head is used for, for example, machine calibration gauges and profile measurements. Moreover, it is known that if a cross spring is used as a fulcrum for supporting the measuring arm, the measurable range can be expanded and high-precision measurement can be achieved.

[0003] In addition, Patent Document 1 describes that, in order to reduce costs, have small deviations in spring characteristics, and facilitate assembly, it is formed from a continuous body, and the continuous body is formed by molding a single plate-shaped elastic body to form a first plate-shaped elastic portion and a second plate-shaped elastic portion that form a cross spring. Prior Art Documents Patent Documents

[0004] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2005-249038 Summary of the Invention Problems to be Solved by the Invention

[0005] The swing fulcrum member described in Patent Document 1 is configured as a continuous body formed by combining two plate-shaped elastic portions, and has excellent characteristics of small deviations and easy assembly. However, the inventors have found that there is still room for improvement in terms of the stability of measurement results and the protection performance of the workpiece surface (workpiece non-damageability) in detectors such as lever type detectors equipped with the swing fulcrum member of Patent Document 1.

[0006] An object of the present disclosure is to provide a measuring head that can obtain excellent stability of measurement results or excellent protection of the workpiece surface when applied to detectors such as lever type detectors. Another object of the present disclosure is to provide a swing fulcrum member. Means for Solving the Problems

[0007] One embodiment of the measuring head of the present disclosure is a measuring head that supports an arm member having a contact at its tip using a swing fulcrum member, and detects the movement amount of the contact by detecting the movement amount of the arm member that performs a seesaw-like movement, characterized in that the swing fulcrum member is formed of a cross-shaped thin plate portion as a cross spring, and a hole is provided so as to penetrate the central portion of the cross spring.

[0008] One embodiment of the swing fulcrum component of the present disclosure is a swing fulcrum component for a measuring head. The measuring head uses the swing fulcrum component to support an arm component with a contact at its top end, and detects the movement amount of the contact by detecting the movement amount of the arm component that performs a seesaw-like movement. The swing fulcrum component is characterized in that the swing fulcrum component is formed as a cross spring by a cross-shaped thin plate portion, and a hole is provided in a manner passing through the central portion of the cross spring. Effects of the Invention

[0009] By adopting the present disclosure, a measuring head that can obtain excellent stability of measurement results or excellent protection of the workpiece surface in the case of being applied to a detector such as a lever-type detector is provided. In addition, by adopting the present disclosure, a swing fulcrum component is also provided. Description of the Drawings

[0010] Figure 1A It is a three-dimensional view showing the stress distribution of the cross spring 10 of the embodiment (with a hole) due to the rotational load around the Z axis. Figure 1B It is a three-dimensional view showing the stress distribution of the cross spring 10 of the embodiment (with a hole) due to the torsional load around the X axis. Figure 1C It is a three-dimensional view showing the stress distribution of the cross spring 10 of the embodiment (with a hole) due to the torsional load around the Y axis. Figure 2A It is a three-dimensional view showing the stress distribution of the conventional cross spring 10 (without a hole) due to the rotational load around the Z axis. Figure 2B It is a three-dimensional view showing the stress distribution of the conventional cross spring 10 (without a hole) due to the torsional load around the X axis. Figure 2C It is a three-dimensional view showing the stress distribution of the conventional cross spring 10 (without a hole) due to the torsional load around the Y axis. Figure 3A It is a three-dimensional view showing the distribution of the deformation amount due to the rotational load around the Z axis in the case of no hole (conventional example). Figure 3B It is a three-dimensional view showing the distribution of the deformation amount due to the rotational load around the Z axis in the case of having a hole (embodiment). Figure 4A It is a three-dimensional view showing the stress distribution due to the torsional load around the X axis in the case of no hole (conventional example). Figure 4B It is a three-dimensional view showing the stress distribution due to the torsional load around the X axis in the case of having a hole (embodiment). Figure 5AIt is a three-dimensional view showing the stress distribution generated by torsional load around the Y-axis in the case of no hole (conventional example). Figure 5B It is a three-dimensional view showing the stress distribution generated by torsional load around the Y-axis in the case of having a hole (embodiment). Figure 6A It is a three-dimensional view showing the distribution of deformation amount in the Y-axis direction (up and down) generated by torsional load around the X-axis in the case of no hole (conventional example). Figure 6B It is a three-dimensional view showing the distribution of deformation amount in the Y-axis direction (up and down) generated by torsional load around the X-axis in the case of having a hole (embodiment). Figure 7A It is a three-dimensional view showing the distribution of deformation amount in the X-axis direction (front and back) generated by torsional load around the Y-axis in the case of no hole (conventional example). Figure 7B It is a three-dimensional view showing the distribution of deformation amount in the X-axis direction (front and back) generated by torsional load around the Y-axis in the case of having a hole (embodiment). Figure 8A It is a three-dimensional view showing the distribution of deformation amount in the Y-axis direction (up and down) generated by torsional load around the X-axis when the crossing angle of the thin plate portion 10-1 in the Y-axis direction is a large angle. Figure 8B It is a three-dimensional view showing the distribution of deformation amount in the Y-axis direction (up and down) generated by torsional load around the X-axis when the crossing angle of the thin plate portion 10-1 in the Y-axis direction is a small angle. Figure 9A It is a three-dimensional view showing the distribution of deformation amount in the X-axis direction (front and back) generated by torsional load around the Y-axis when the crossing angle of the thin plate portion 10-1 in the Y-axis direction is a large angle. Figure 9B It is a three-dimensional view showing the distribution of deformation amount in the X-axis direction (front and back) generated by torsional load around the Y-axis when the crossing angle of the thin plate portion 10-1 in the Y-axis direction is a small angle. Figure 10 It is a cross-sectional view of the measuring head 80 using the leaf spring 10. Figure 11 It is a three-dimensional view showing the situation of measurement using the measuring head 80 during the processing of the workpiece W. Detailed Embodiment

[0011] The first embodiment of the measuring head of the present disclosure is a measuring head that supports an arm member with a contact at its tip using a swing fulcrum member, and detects the movement amount of the contact by detecting the movement amount of the arm member that performs a seesaw-like movement. It is characterized in that the swing fulcrum member is constituted by a cross-shaped thin plate portion as a cross spring, and a hole is provided so as to penetrate the central portion of the cross spring.

[0012] The second embodiment of the measuring head of the present disclosure is based on the first embodiment, and is characterized in that the diameter of the hole is 1 / 4 - 1 / 2 of the width of the cross spring in terms of the block width H.

[0013] The third embodiment of the measuring head of the present disclosure is based on the first or second embodiment, and is characterized in that the shape of the hole is a long hole or a polygon, and an arc is provided around the hole.

[0014] The fourth embodiment of the measuring head of the present disclosure is based on the first or second embodiment, and is characterized in that the cross spring is integrated by cutting metal using wire electrical discharge machining.

[0015] The fifth embodiment of the measuring head of the present disclosure is based on the first or second embodiment, and the crossing angle in either the X-axis direction or the Y-axis direction of the cross spring is smaller than the crossing angle in the other direction.

[0016] The first embodiment of the swing fulcrum member of the present disclosure is a swing fulcrum member for a measuring head. The measuring head supports an arm member with a contact at its tip using the swing fulcrum member, and detects the movement amount of the contact by detecting the movement amount of the arm member that performs a seesaw-like movement. It is characterized in that the swing fulcrum member is constituted by a cross-shaped thin plate portion as a cross spring, and a hole is provided so as to penetrate the central portion of the cross spring.

[0017] The second embodiment of the swing fulcrum member of the present disclosure is based on the first embodiment, and is characterized in that the diameter of the hole is 1 / 4 - 1 / 2 of the width of the cross spring in terms of the block width H.

[0018] The third embodiment of the swing fulcrum member of the present disclosure is based on the first or second embodiment, and the crossing angle in either the X-axis direction or the Y-axis direction of the cross spring is smaller than the crossing angle in the other direction.

[0019] Next, the embodiments will be described in detail with reference to the drawings. Figures 1A - 1C is a three-dimensional view showing the stress distribution (when a load is applied around each axis) of the cross spring 10 of the embodiment due to the load around each axis, Figure 1A is the case where a rotational load is applied, Figure 1BThis is the case where a torsional load (about the X-axis) is applied. Figure 1C This is the case where a torsional load (about the Y-axis) is applied. It should be noted that the rotational load refers to the rotational load about the Z-axis in Figures 1A - 1C as described later in Figure 10 and is equivalent to the measurement direction ( Figure 10 direction A) measured by the measuring head 80 having the cross spring 10 as described later.

[0020] Figures 1A - 1C The cross spring 10 shown is an integral part obtained by wire cutting (machining) a metal material. The metal material can use stainless steel and other metals. Other metals (such as iron) are preferably subjected to anti-rust plating after wire cutting. The cross spring 10 is composed of a cross-shaped thin plate portion 10-1. In addition, the embodiment of FIG. 1 (including Figures 1A - 1C ) is characterized in that a hole is provided so as to penetrate the central portion 10-3 of the cross fulcrum.

[0021] The inventors of the present invention found that even when using a swing fulcrum member having excellent characteristics as described in Patent Document 1, there is still room for improvement in the stability of the measurement result and / or the protection performance of the workpiece surface when applied to a lever-type detector or the like, and they conducted in-depth research on the reasons. As a result, it was found that there is a correlation between the stiffness in the rotation direction (about the Z-axis, measurement direction) of the swing fulcrum member and the above performance. That is, it was found that when the stiffness in the rotation direction is large, the force (measurement force) pressing the contact 85 against the workpiece fluctuates greatly, so the measurement result sometimes becomes unstable. In addition, regarding the protection performance of the workpiece surface, it was also found that when the stiffness in the rotation direction is large and the measurement force is too large, there is a tendency to easily damage the workpiece surface.

[0022] Based on the above new findings, the inventors of the present invention explored a new structure in order to adjust the stiffness in the rotation direction of the swing fulcrum member. As a result, as described above, by providing a hole so as to penetrate the central portion 10-3 of the cross fulcrum, it was successfully achieved to adjust (reduce) the stiffness in the rotation direction (about the Z-axis) while maintaining the stiffness in the torsional direction with respect to torsion about the X-axis and about the Y-axis. Hereinafter, with reference to the drawings, the measuring head and the swing fulcrum member of the embodiment will be described in detail.

[0023] Figure 10 This is a cross-sectional view of the measuring head 80 using the cross spring 10. The cross spring 10 is held in contact with both the arm member 83 and the measuring head main body 81 so as to be sandwiched therebetween and functions as a swing fulcrum of the measuring head 80. A finger portion 84 is installed at the top end of the arm member 83, and a contact 85 is installed at the top end of the finger portion 84. A core 86 of a differential transformer is installed at the rear end of the arm member 83, and a coil 87 of the differential transformer is installed on the measuring head main body 81.

[0024] In addition, a compression coil spring 88 is provided between the measuring head main body 81 and the arm member 83 to apply a measuring pressure to the contact 85, and the swing lower end of the arm member 83 is set by a set screw 89 provided on the measuring head main body 81.

[0025] Since the measuring head 80 makes a seesaw-like movement with the cross spring 10 as a fulcrum by the arm member 83, the movement amount of the contact 85 when the contact 85 contacts the workpiece W can be detected by a differential transformer, and high-precision measurement can be performed.

[0026] During this measurement, torsional loads are applied to the cross spring 10 due to the surface roughness of the measurement surface of the workpiece, external vibrations, the contact between the contact 85 and the workpiece, and the deviation of the measurement position. In order to stabilize the measurement value of the measuring head 80, the cross spring 10 preferably has excellent stiffness (torsional stiffness) against this torsional load. On the other hand, as already described, from the viewpoints of stabilizing the measurement value and the workpiece surface protection performance, the cross spring 10 is preferably soft (reduced stiffness) in the rotational direction (measurement direction). The cross spring 10 needs to have the opposite mechanical properties as described above.

[0027] Figure 11 is a perspective view showing the situation where measurement is performed using the measuring head 80 during the machining process of the workpiece W. Using Figure 11 Explain again the above-mentioned mechanical properties required for the cross spring 10. The cross spring 10 is soft so that the rotational load (measurement direction: Figure 10 arrow A in) i.e., the same deformation can be obtained with a smaller load around the Z axis. On the other hand, the stiffness must be high against torsional loads around the X axis and around the Y axis.

[0028] Figures 2A - 2C is a perspective view showing the stress distribution of the conventional cross spring 10. Similar to Figures 1A - 1C the embodiment of, metal is cut by wire electrical discharge machining so that the cross spring 10 is integrated, but no hole is provided in the central portion of the thin plate portion 10-1. Other conditions except for the presence or absence of the hole, such as the plate thickness, length, and crossing angle of the thin plate portion 10-1, are the same. In Figures 2A - 2C the darker color indicates greater stress.

[0029] As Figure 2A shown, the portions where the stress increases due to the rotational load are near the crossing portion of the thin plate portion 10-1 and near the root portion 10-2 of the thin plate portion 10-1, and the color is darker than Figure 2A other parts in.

[0030] As Figure 2BAs shown, the portion with relatively small stress generated by the torsional load around the X-axis is near the central portion 10-3 of the thin plate portion 10-1. In Figure 2B the color of the vicinity of the central portion 10-3 becomes lighter from bottom to top. It can be seen that stress generated by the torsional load around the Y-axis is also generated at the root portion 10-2 of the thin plate portion 10-1.

[0031] Regarding Figures 2A - 2C the non-perforated cross spring 10, in Figures 1A - 1C the embodiment, a hole is provided in a manner that penetrates the central portion of the cross spring 10 (in the block width H direction (Z-axis direction) and the height direction (Y-axis direction)). That is, a hole is provided at a position where the stress generated by the rotational load is relatively large. As a result, in Figures 1A - 1C the embodiment, the stress generated by the rotational load becomes larger. It is relatively difficult to distinguish the change between Figures 1A - 1C and Figures 2A - 2C , but in Figures 1A - 1C the maximum value (calculated value) of the (von Mises) stress is about 1.2 times that in the case of Figures 2A - 2C . On the other hand, the magnitude of the stress generated by the torsional load does not change in terms of rotation around the X-axis and around the Y-axis, and the distribution does not have a large difference (the stiffness is maintained).

[0032] Figure 3A and Figure 3B are three-dimensional views showing the distribution of the amount of deformation generated by the rotational load in the case of non-perforated (conventional example, Figure 3A ) and perforated (embodiment, Figure 3B ) respectively. In Figure 3A and Figure 3B , a darker color indicates a larger amount of deformation. Figure 3B It is shown that by providing a hole near the central portion 10-3, the overall color becomes darker, indicating that the amount of deformation generated by the same rotational load becomes larger. The amount of deformation generated by the same rotational load becomes larger. In other words, it means that in the case of the perforated cross spring 10, the rotational load (measurement direction: Figure 10 arrow A in

[0033] Figure 4A and Figure 4B are three-dimensional views showing the stress distribution generated by the torsional load around the X-axis in the case of non-perforated (conventional example, Figure 4A ) and perforated (embodiment, Figure 4B ) respectively. In Figure 4A and Figure 4B , a darker color indicates a larger stress. From Figure 4A , Figure 4BFrom the comparison, it can be seen that the magnitude of the stress generated by the torsional load around the X-axis hardly changes between the previous example and the present embodiment, and there is no significant difference in the distribution. That is, with respect to the torsional load around the X-axis, since little stress is applied to the center of the thin plate portion of the cross spring 10, even if a hole is provided, its stiffness remains unchanged. This was previously unknown and was first confirmed through the construction of a refined verification model supported by the new ideas of the inventors of the present invention and advanced simulation techniques.

[0034] Figure 5A , Figure 5B is a three-dimensional diagram comparing the stress distributions generated by the torsional load around the Y-axis in the case of no hole (previous example, Figure 5A ) and with a hole (embodiment, Figure 5B ). In Figure 5A , Figure 5B , a darker color indicates a greater stress. From Figure 5A and Figure 5B , it can be seen that the magnitude of the stress generated by the torsional load around the Y-axis hardly changes between the previous example and the embodiment, and there is no significant difference in the distribution. That is, with respect to the torsional load around the Y-axis, since little stress is applied to the center of the thin plate portion of the cross spring 10, even if a hole is provided, its stiffness remains unchanged. This is the same as the above-mentioned torsional load around the X-axis and was previously unknown.

[0035] Figure 6A , Figure 6B is a three-dimensional diagram comparing the distribution of the deformation amount in the Y-axis direction generated by the torsional load around the X-axis in the case of no hole (previous example, Figure 6A ) and with a hole (embodiment, Figure 6B ). In Figure 6A and Figure 6B , the shade of the color indicates the deformation amount and its direction. That is, a darker-colored part indicates a greater deformation amount in the upward (positive direction of the Y-axis), and a lighter-colored part indicates a greater deformation amount in the downward (negative direction of the Y-axis) (it should be noted that the following Figure 8A , Figure 8B is the same as the above). According to Figure 6A , Figure 6B , it can be seen that the shade distribution is roughly (almost) the same, and with respect to the deformation amount in the Y-axis direction generated by the torsional load around the X-axis, its amount and direction hardly change between the previous example and the embodiment.

[0036] Figure 7A , Figure 7B is a three-dimensional diagram comparing the distribution of the deformation amount in the X-axis direction generated by the torsional load around the Y-axis in the case of no hole (previous example, Figure 7A ) and with a hole (embodiment, Figure 7B ). In Figure 7Aand Figure 7B In Figure 7B , the shade of the color indicates the amount and direction of deformation. That is, the darker part of the color indicates a larger amount of deformation in the depth direction (the positive direction of the X-axis), and the lighter part of the color indicates a larger amount of deformation in the forward direction (the negative direction of the X-axis). (It should be noted that the following Figure 9A Figure 9A , Figure 9B is the same as the above situation). According to Figure 7A Figure 7A , Figure 7B , it can be known that the distribution of their shades is roughly the same. Regarding the amount and direction of the deformation in the X-axis direction caused by the torsional load around the Y-axis, there is almost no change in the amount and direction in the conventional example and the embodiment.

[0037] As described above, when comparing the case where a hole is provided in a manner passing through the center of the cross fulcrum (embodiment) with the case without a hole (conventional example), for the torsional load which is the load "other than" the measurement direction of the cross spring 10, the magnitude of the stress remains unchanged. In the rotational direction (measurement direction) of the cross spring 10, the stress increases due to the load. That is, in the measurement direction, since the same deformation can be obtained with a smaller load, the cross spring 10 is flexible, and the cross spring 10 can maintain stiffness with respect to torsional loads in other directions, around the X-axis, and around the Y-axis.

[0038] Therefore, when the same load is applied in the rotational direction of the cross fulcrum, compared with the fulcrum without a hole (conventional example), the deformation of the fulcrum with a hole provided (embodiment) becomes larger, and the same deformation can be obtained with a smaller load, so the reaction force on the cross fulcrum becomes smaller. In addition, when comparing the case where a hole is provided in a manner passing through the center of the cross fulcrum (embodiment) with the case without a hole (conventional example), when the same load is applied in the torsional direction, the stress in any torsional direction will not change greatly (maintaining stiffness).

[0039] That is, the stress corresponding to the torsional load at the center of the thin plate portion 10-1 of the cross spring 10 is small. Therefore, even if a hole is provided in the central portion, the influence on the torsional stiffness is small. Moreover, the fulcrum with a hole provided (embodiment) can reduce the fulcrum reaction force without reducing the stiffness, or increase the stiffness without increasing the fulcrum reaction force. Thus, the selection of materials is also more extensive. Furthermore, while increasing the deformation amount in the measurement direction, the necessary load can be suppressed to be smaller.

[0040] Moreover, the effect of obtaining the same deformation with a smaller load and having sufficient stiffness against torsional loads in other directions, that is, the effect of having higher sensitivity in the measurement direction and increased stiffness in other directions, can be adjusted by the size of the holes. Moreover, the diameter of the holes is not particularly limited. As one way, the diameter of the holes can be about 1 / 4 - 1 / 2 of the block width H of the cross spring 10, preferably about 1 / 3 of the width. For example, if the block width H is 12 mm, the hole diameter is more preferably 3 mm - 6 mm in practical use.

[0041] In addition, the shape of the holes is not limited to round holes, and can also be long holes or polygons, but round holes or long holes are preferred. The periphery of the holes preferably has an arc. By rounding the periphery of the holes, it is easier to prevent unnecessary stress concentration and further suppress fractures. It should be noted that in the case where the shape of the holes is polygonal, "the periphery of the holes has an arc" means that there is an arc at the corner part.

[0042] Furthermore, the hole position is preferably at the central part in the direction of the block width H (Z-axis direction). On the other hand, as Figure 4A , Figure 4B , Figure 5A , Figure 5B shows, as long as it is in the range where there is almost no stress (virtually no stress) under torsional loads (X-axis, Y-axis) and the color is lighter, if it is in the range from the central part of the cross fulcrum to about 1 / 4 of the block width H, it is a more preferably hole position in practical use.

[0043] In addition, for the cross spring 10 integrated by cutting using wire electrical discharge machining, due to the opening of the holes, the number of processing steps increases compared with the past. However, during the blank processing before processing the thin plate part 10 - 1, an automatic machine can be used for corresponding. Moreover, considering the overall processing time, the wire cutting processing time of the thin plate part 10 - 1 is longer. In contrast, the time for opening the holes is shorter, and the hole opening processing does not significantly increase the cost.

[0044] Moreover, from the perspective of hardly applying stress to the central part, adopting a structure with multiple independent cross springs separated in the direction of the block width H (Z-axis direction) can also achieve the same effect. However, the assembly of the cross fulcrum must be carried out with high precision, and it is advantageous in that the assembly can be carried out more easily in the embodiment shown in the figure.

[0045] Figure 8A , Figure 8B and Figure 9A , Figure 9B are perspective views respectively comparing and showing the deformation amount distributions caused by different crossing angles of the thin plate part 10 - 1. In addition, Figure 8A , Figure 8B and Figure 9A ,Figure 9B It is a diagram for explaining the distribution of deformation amounts caused by different crossing angles, and uses a conventional cross spring without a hole opened in a way that penetrates the central part.

[0046] Figure 8A 、 Figure 8B It shows the deformation amount in the up-and-down (Y-axis) direction caused by a torsional load (around the X-axis), Figure 9A 、 Figure 9B and shows the deformation amount in the front-and-back (X-axis) direction caused by a torsional load (around the Y-axis). From Figure 8A 、 Figure 8B it can be seen that when the crossing angle in the Y-axis direction is a narrow angle ( Figure 8B ), the deformation amount in the up-and-down (Y-axis) direction caused by a torsional load (around the X-axis) is smaller. From Figure 9A 、 Figure 9B it can be seen that when the crossing angle in the X-axis direction is a narrow angle ( Figure 9A ), the deformation amount in the front-and-back (X-axis) direction caused by a torsional load (around the Y-axis) is smaller. On the other hand, if the crossing angle is approximately 90°, the tolerance (stiffness) against torsional loads in all directions is further improved, so it is preferred.

[0047] That is, if the friction direction for friction from the measurement object is a torsional load (X-axis), when the crossing angle in the Y-axis direction is a narrow angle, the stiffness is more improved, so it is preferred. Conversely, if the friction direction is a torsional load (Y-axis), when the crossing angle in the X-axis direction is a narrow angle, the stiffness is more improved, so it is preferred. Thus, by making the crossing angle in either the X-axis direction or the Y-axis direction smaller than the crossing angle in the other direction, the stiffness can be improved with respect to a specific axis direction, and thus the measurement value can be more effectively suppressed from becoming unstable due to external vibrations and impacts when the contact head contacts the object to be measured.

[0048] The above Figure 8A 、 Figure 8B and Figure 9A 、 Figure 9B The results are described using a conventional cross spring, but the same tendency also exists in the cross spring of the embodiment having a hole in a way that penetrates the central part. From Figure 8A 、 Figure 8B and Figure 9A 、 Figure 9B In the reference examples, it can be seen that the stiffness (effect of suppressing deformation) related to the torsional load (around the X-axis) and the torsional load (around the Y-axis) can be fully obtained. This is also the same for the cross spring of the embodiment (i.e., maintained). ​​​​​​​​On the other hand, although the results are not shown, as described above, the cross spring of the embodiment having a hole penetrating the central portion suppresses the stiffness related to the rotation direction (measurement direction) to a lower level compared to the cross spring of the conventional example, and thus is excellent. Description of Reference Numerals

[0049] 10: Cross spring; 10-1: Thin plate portion; 10-2: Root portion; 10-3: Central portion; 80: Measuring head; 81: Measuring head body; 83: Arm member; 84: Finger portion; 85: Contact; 86: Iron core; 87: Coil; 88: Compression coil spring; 89: Set screw; H: Block width; W: Workpiece.

Claims

1. A measuring head that supports an arm member with a contact at its tip using a swing fulcrum member, and detects the movement amount of the contact by detecting the movement amount of the arm member that performs a seesaw-like movement. Characterized in that The swing fulcrum member is formed of a cross-shaped thin plate portion as a cross spring, and a hole is provided so as to penetrate the central portion of the cross spring.

2. The measuring head according to claim 1, Characterized in that The diameter of the hole is 1 / 4 - 1 / 2 of the width of the cross spring in terms of the block width H.

3. The measuring head according to claim 1 or 2, Characterized in that The shape of the hole is a long hole or a polygon, and the periphery of the hole has an arc.

4. The measuring head according to claim 1 or 2, Characterized in that The cross spring is integrated by cutting metal using wire electrical discharge machining.

5. The measuring head according to claim 1 or 2, Characterized in that The crossing angle in either the X-axis direction or the Y-axis direction of the cross spring is smaller than the crossing angle in the other direction.

6. A swing fulcrum member, Characterized in that It is used for a measuring head that supports an arm member with a contact at its tip using the swing fulcrum member, and detects the movement amount of the contact by detecting the movement amount of the arm member that performs a seesaw-like movement. The swing fulcrum member is characterized in that The swing fulcrum member is formed of a cross-shaped thin plate portion as a cross spring, and a hole is provided so as to penetrate the central portion of the cross spring.

7. The swing fulcrum member according to claim 6, Characterized in that The diameter of the hole is 1 / 4 - 1 / 2 of the width of the cross spring in terms of the block width H.

8. The swing fulcrum member according to claim 6 or 7, Characterized in that The crossing angle in either the X-axis direction or the Y-axis direction of the cross spring is smaller than the crossing angle in the other direction.

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