Vernier caliper force measuring device

Abstract

This invention provides a detachable vernier caliper force detection device for detecting the measuring force of a vernier caliper. The vernier caliper force detection device (100) includes: a fixed unit (120) fixedly mounted to the vernier caliper in a manner that prevents relative displacement with respect to the vernier caliper (520); a movable unit (300) configured to allow slight relative displacement with respect to the fixed unit in a direction parallel to the movement direction of the vernier caliper; and pressure detection components (410, 420) disposed between the fixed unit and the movable unit and configured to detect pressure applied in a direction parallel to the movement direction of the vernier caliper. The movable unit has an alternative handle (360) disposed near the handle (530) of the vernier caliper, thereby replacing the handle of the vernier caliper as an operating part for pushing and pulling the vernier caliper.

Description

Technical Field

[0001] This invention relates to a vernier caliper measuring force detection device that is detachably mounted on the vernier of a vernier caliper and detects the measuring force of the vernier caliper. Background Technology

[0002] Vernier calipers exist as small measuring devices (tools) for measuring the dimensions of workpieces (objects to be measured). When using vernier calipers to measure the dimensions of a workpiece (object to be measured), the user places their fingers on the operating part of the vernier and pushes or pulls it to make the vernier slide, causing the measuring jaws to come into contact with the measuring part of the workpiece (object to be measured). Therefore, the pushing force (measuring pressure) applied to the workpiece (object to be measured) may vary depending on the user, resulting in deviations in the measured value.

[0003] Therefore, a vernier caliper (measuring device) with a mechanism for stabilizing the measured pressure has been proposed. For example, in Patent Document 1 (Japanese Patent Publication No. 55-11442), a vernier caliper with a pressure detection mechanism and a pressure display (measurement pressure display unit) assembled on the outside of the main scale using measuring jaws is proposed. Furthermore, in Patent Documents 2, 3, and 4 (Japanese Patent 2593029, Japanese Patent 5095155, and Japanese Patent 6381369), a vernier caliper with a pressure-regulating mechanism assembled on the handle of the vernier is proposed. The pressure-regulating mechanism is, for example, a spring mechanism that allows freewheeling when the force applied from the finger to the vernier exceeds a predetermined value.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application No. 55-11442

[0007] Patent Document 2: Japanese Patent 2593029

[0008] Patent Document 3: Japanese Patent 5095155

[0009] Patent Document 4: Japanese Patent No. 6381369 Summary of the Invention

[0010] The problem the invention aims to solve

[0011] As in Patent Document 1, if a pressure detection mechanism and a pressure display (pressure display unit) are assembled on the outside of the main scale using measuring jaws, the size, weight, and price of the vernier caliper itself will all increase. Furthermore, since the vernier caliper's measurement value is displayed on the vernier side (or obtained by reading the scale), the measurement operation involves significant line-of-sight movement while reading the pressure display on the outer measuring jaws, thus also resulting in a lack of improved measurement efficiency.

[0012] If a constant pressure mechanism is assembled into the handle of the vernier caliper (Patent Documents 2-4), there will be a problem that the actual measuring force applied to the workpiece (the object being measured) will be deviated due to the deviation of the sliding resistance inherent in the vernier caliper itself. In addition, the measuring person will find it difficult to know the contact between the jaws and the workpiece, and will not be able to feel the actual degree of force applied to the workpiece.

[0013] The purpose of this invention is to solve the existing problems and to provide a vernier caliper measuring force detection device that can be easily installed on the vernier of a vernier caliper and detects the measuring force of the vernier caliper.

[0014] Solution for solving the problem

[0015] The vernier caliper force measuring device (100) of the present invention is detachably mounted on the vernier scale (520) of a vernier caliper (500) and measures the measuring force of the vernier caliper (500). The device is characterized by comprising: a fixed unit (120) fixedly mounted on the vernier scale (520) in a manner that does not cause relative displacement with respect to the vernier scale (520); and a movable unit (300) configured to be slightly movable relative to the fixed unit (120) in a direction parallel to the direction of movement of the vernier scale (520). Micro-relative displacement; and pressure detection components (410, 420) disposed between the fixed unit (120) and the movable unit (300) and configured to detect pressure applied in a direction parallel to the moving direction of the vernier (520), the movable unit (300) having a substitute handle (360) disposed near the handle (530) of the vernier (520) to replace the handle (530) of the vernier (520) and become an operating part for pushing and pulling the vernier (520).

[0016] In one embodiment of the present invention, preferably, a first elastic body and a second elastic body (341, 342) are provided between the movable unit (300) and the fixed unit (120). The first elastic body and the second elastic body (341, 342) apply equal forces to the movable unit (300) from two directions in a direction parallel to the moving direction of the vernier (520) in such a way that the relative position of the movable unit (300) with respect to the fixed unit (120) is a predetermined neutral position.

[0017] In one embodiment of the present invention, preferably, one of the fixed unit (120) and the movable unit (300) is provided with a guide groove (151, 251) or a protrusion extending in a direction parallel to the moving direction of the vernier (520), and the other of the fixed unit (120) and the movable unit (300) is provided with a protrusion (321, 322) or a groove, which is fitted into the guide groove (151, 251) or the protrusion and slides in a direction parallel to the moving direction of the vernier (520).

[0018] In one embodiment of the present invention, preferably, the fixing unit (120) has a housing portion (130) fixedly fixed to the back side of the vernier (520). The lower end face of the housing portion (130) is open to receive a portion of the movable unit (300), and a receiving space is defined inside the housing portion (130). Furthermore, the housing portion (130) has one end sidewall (170, 270) and another end sidewall (180, 280), which are perpendicular to the moving direction of the vernier (520) and are spaced apart by a predetermined interval in the moving direction of the vernier (520). Yes, the pressure detection components (410, 420) include a first pressure detection element (410) and a second pressure detection element (420). The first pressure detection element (410) is configured to be pressed against one end sidewall (170, 270) inside the housing portion (130), and the second pressure detection element (420) is configured to be pressed against the other end sidewall (180, 280) inside the housing portion (130). A first elastic body (341) is disposed between the first pressure detection element (410) and the movable unit (300), and a second elastic body (342) is disposed between the second pressure detection element (420) and the movable unit (300).

[0019] In one embodiment of the present invention, preferably, a support shaft (330) is provided inside the housing portion (130). The support shaft (330) is fixed in a direction parallel to the moving direction of the vernier (520) by being mounted on one end side wall (170, 270) and the other end side wall (180, 280). The movable unit (300) has a through hole through which the support shaft (330) passes and is allowed to move along the support shaft (330) in a direction parallel to the moving direction of the vernier (520).

[0020] In one embodiment of the present invention, it is preferred that when the pressure sensing element (410, 420) detects a predetermined measuring force, the user is notified by sound or light from the vernier caliper force sensing device (100) or the vernier caliper (500).

[0021] In one embodiment of the present invention, it is preferred that when the pressure sensing element (410, 420) detects a predetermined measuring force, the vernier caliper measuring force sensing device (100) locks the measured value in the vernier caliper (500). Attached Figure Description

[0022] Figure 1 This is a diagram observed from the front side of the vernier caliper force measuring device.

[0023] Figure 2 This is a diagram observed from the back side of the vernier caliper force measuring device.

[0024] Figure 3 This diagram illustrates the state of the connection unit installed on a vernier caliper.

[0025] Figure 4 This diagram illustrates the state of a vernier caliper with a force measuring device installed.

[0026] Figure 5 This is a diagram showing the vernier caliper with the force measuring device installed, viewed from the front side.

[0027] Figure 6 This is a diagram showing the vernier caliper with the vernier force measuring device installed, viewed from the back side of the vernier caliper (the front side of the vernier caliper force measuring device).

[0028] Figure 7 This is an exploded perspective view of a vernier caliper force measuring device.

[0029] Figure 8 This is a diagram showing the inner surface of the first cover.

[0030] Figure 9 This is a diagram showing a component unit with a pressure sensing element installed in the movable unit.

[0031] Figure 10 yes Figure 1 The XX-line sectional view in the diagram.

[0032] Figure 11 This diagram illustrates a state where no external force from the fingers is applied to the force detection device (alternative hand rest) of the vernier caliper and the vernier caliper's vernier scale.

[0033] Figure 12 This diagram illustrates the state when the alternative armrest is slowly pushed to one side.

[0034] Figure 13 This diagram illustrates the action of measuring the inner diameter (inner dimension) of a workpiece.

[0035] Explanation of reference numerals in the attached figures

[0036] 100. Measuring force detection device (vernier caliper measuring force detection device); 120. Fixing unit; 130. Housing part; 140. First cover; 150. First base surface; 151. First guide groove; 160. First upper end surface; 161. Connection port opening; 162. Threaded hole; 170. First one-end side wall surface; 180. First other-end side wall surface; 190. Circuit part; 191. Circuit base 192. Plate; 193. Connection port; 194. Buzzer; 245. Second cover; 256. Second base surface; 257. Second guide groove; 268. Second upper end surface; 279. Second one-end side wall surface; 280. Second other-end side wall surface; 300. Movable unit; 310. Movable base plate; 321. Sliding travel block; 322. First protrusion; 323. Second protrusion; 344. Support shaft; 342. First spring; 350. Operating part; 360. Alternate handle part; 361. Upper pressure plate part; 362. Lower pressure plate part; 363. Hole part; 370. Auxiliary movable plate part; 410. First pressure sensing element; 420. Second pressure sensing element; 500. Vernier caliper; 510. Main scale; 511. Outer measuring jaw; 512. Inner measuring jaw; 520. Vernier; 521. Outer measuring jaw; 522. Inner measuring jaw; 523. Display panel; 524. Operating switch; 530. Handle part; 531. Pin; 532. Protrusion piece; 540. Connection port; 550. Circuit part; 600. Connection unit; 610. Connection unit main body part; 611. Threaded fixing hole; 620. Connector terminal for measuring equipment; 630. Connector terminal for external equipment. Detailed Implementation

[0037] Embodiments of the present invention are illustrated, and the embodiments of the present invention are described with reference to the reference numerals indicating the elements in the figures.

[0038] (First Embodiment)

[0039] Figure 1 This is a diagram observed from the front side of the vernier caliper force measuring device.

[0040] Figure 2 This is a diagram observed from the back side of the vernier caliper force measuring device.

[0041] The vernier caliper force measuring device 100 of this embodiment can be attached to or detached from the vernier caliper 500 as needed, and is used to make the vernier caliper 500, which does not have a built-in pressure sensor, the same as a vernier caliper with a constant pressure mechanism.

[0042] In the following description, the vernier caliper force measuring device 100 will be referred to simply as "force measuring device 100".

[0043] Also refer to Figures 3-6 .

[0044] Figure 3 This diagram illustrates the state in which the connecting unit 600 is installed on the vernier caliper 500.

[0045] Figure 4 This diagram illustrates the state in which the force measuring device 100 is installed on the vernier caliper 500.

[0046] Figure 5 This is a view of the vernier caliper 500 with the force measuring device 100 installed, observed from the front side.

[0047] Figure 6 This is a view of the vernier caliper 500 with the force measuring device 100 installed, observed from the back side of the vernier caliper 500 (the front side of the force measuring device 100).

[0048] Figure 3 The vernier caliper 500 and the connecting unit 600 are shown.

[0049] The Vernier 500 has a main scale of 510 and a vernier scale of 520.

[0050] The main scale 510 is a narrow and elongated flat plate component. Graduation along its length is provided on the surface of the main scale 510. An outer measuring jaw 511 is provided on the lower edge of one end of the main scale 510, and an inner measuring jaw 512 is provided on the upper edge.

[0051] In this embodiment, a digital vernier caliper 500 is assumed, therefore an encoder scale is provided on the main scale 510 along the length direction. As encoders, known detection methods include electromagnetic induction encoders, photoelectric encoders, electrostatic capacitive encoders, and magnetic encoders.

[0052] The vernier 520 is configured to slide along the length of the main scale 510.

[0053] An outer measuring jaw 521 is provided on the lower edge side of one end of the vernier 520, and an inner measuring jaw 522 is provided on the upper edge side.

[0054] A display panel 523 for displaying measurement values ​​and an operation switch 524 are arranged on the surface side of the vernier 520. Additionally, a handle 530, serving as an operating part 350 for pushing and pulling the vernier 520, is provided on the lower edge of the other end of the vernier 520. Here, the handle 530 is convexly bulging downwards from the lower edge of the vernier 520, and its surface has small, non-slip irregularities.

[0055] The vernier 520 has a connection port 540 on its upper surface for inserting the connector terminals of the connection unit 600. Furthermore, threaded holes 541 are provided on both sides of the connection port 540. A circuit section 550 is built into the vernier 520.

[0056] The circuit section 550 includes, for example, a detection head for detecting scale signals from the scale, a display control section for controlling the display panel 523, and a communication control section for controlling communication with external devices. Additionally, a battery is installed inside the vernier 520.

[0057] Next, the connection unit 600 will be described.

[0058] The connection unit 600 itself is also disclosed, for example, in the applicant's Japanese Patent 6650860.

[0059] The connection unit 600 has a flat rectangular body 610 and two connector terminals 620 and 630 provided on the body 610.

[0060] One of the two connector terminals (620, 630), connector terminal 620, is the connector terminal that connects to the connection port 540 of the vernier caliper 500 (connector terminal 620 for measuring equipment). The other connector terminal (630) is the connector terminal that connects to the connection port 161 of an external device (here, the force measuring device 100) (connector terminal 630 for external device). On the lower surface of the connection unit body 610, the connector terminal 620 for measuring equipment and the connector terminal 630 for external device are positioned to protrude in the same direction on the same surface (here, the lower surface) of the connection unit body 610. In the top view of the connection unit body 610, through threaded fixing holes 611 are provided at the four corners.

[0061] Observe only the attached figures (e.g.) Figure 6 It can be seen that when the vernier caliper 500 and the force measuring device 100 are connected using the connecting unit 600, the surface of the vernier caliper 500 (vernier 520) with the connection port 540 and the surface of the force measuring device 100 with the connection port 161 become approximately flush planes when their relative positions are matched. Therefore, the lower surface of the connecting unit body 610 is formed as a generally flat surface, thereby matching this flush plane. Here, the dimensions of the connecting unit body 610 and the relative distance between the connector terminal 620 for the measuring device and the connector terminal 630 for the external device are designed so that the positional relationship between the force measuring device 100 and the vernier caliper 500 (vernier 520) is optimal when the force measuring device 100 is mounted on the vernier caliper 500 (vernier 520).

[0062] Here, it is assumed that the force measuring device 100 and the back of the vernier 520 are in close contact, but it is not necessary for the force measuring device 100 and the vernier 520 to abut against each other; there can also be a gap between the force measuring device 100 and the vernier 520. In short, the force measuring device 100 can be fixedly held on the back side of the vernier 520 by means of the connecting unit 600.

[0063] Reference Figures 3-6 First, let me explain the steps for installing the force measuring device 100 onto the vernier caliper 500.

[0064] First, such as Figure 3 As illustrated, the connecting unit 600 is mounted on the vernier 520 of the vernier caliper 500.

[0065] The measuring device connector terminal 620 of the connection unit 600 is connected to the connection port 540 of the vernier 520. Furthermore, the connection unit 600 and the vernier 520 are pre-secured using two screws. Next, as... Figure 4 As illustrated, the force measuring device 100 is mounted on the vernier 520 of the vernier caliper 500. That is, the force measuring device 100 is mounted on the connection unit 600. The external device connector terminal 630 of the connection unit 600 is connected to the connection port 161 of the force measuring device 100. Then, the two sides of the external device connector terminal 630 are secured with screws.

[0066] In addition, Figure 4 In this device, a pin 531 is provided on the back side of the handle portion 530 of the vernier 520. Normally, this is the part where the back side component of the handle portion 530 is fitted, and the pin 531 is a fastening pin 531 (boss) for the back side component. This pin 531 is inserted into the hole 363 of the alternative handle portion 360 of the force measuring device 100 (details will be described later). This completes the installation of the force measuring device 100 onto the vernier caliper 500 (vernier 520).

[0067] For example, power is supplied from the vernier caliper 500 to the force measuring device 100. The force measuring device 100 sends a data latching signal based on the measured pressure to the vernier caliper 500.

[0068] (Force measuring device 100)

[0069] The structure of the force measuring device 100 will be described.

[0070] For ease of understanding, such as Figure 6 As shown, a three-axis XYZ coordinate system with mutually orthogonal axes is adopted. Now, taking the vernier 520 of the vernier caliper 500 as a reference when the force measuring device 100 is mounted, the X-axis is taken in the direction parallel to the main scale 510 (the direction of movement of the vernier 520). The Y-axis is taken in the direction penetrating the vernier caliper 500 from the front side to the back side of the vernier caliper 500. In other words, the Y-axis is taken in the direction penetrating the force measuring device 100 from the back side to the front side of the force measuring device 100. Then, the height direction is set as the Z-axis.

[0071] Reference Figure 1 , Figure 2 Overall three-dimensional view of the force measuring device 100 and Figures 7-9 .

[0072] Figure 7 This is an exploded perspective view of the force measuring device 100.

[0073] The force measuring and detection device 100 includes a fixed unit 120, a movable unit 300, and pressure detection elements (pressure detection components) 410 and 420.

[0074] The fixing unit 120 is a cuboid shape with internal space.

[0075] The fixed unit 120 is rectangular in shape, and its length (lateral width) in the X-axis direction is shorter than that in the X-axis direction of the vernier 520. The length (thickness) in the Y-axis direction of the fixed unit 120 is relatively thin. Being as thin as possible will not affect the operability of the vernier caliper 500, so it is preferred.

[0076] The length (height) of the fixed unit 120 in the Z-axis direction is approximately the same as the length (height) of the vernier 520 in the Z-axis direction. That is, when the force measuring device 100 is installed on the vernier 520 of the vernier caliper 500, the upper end face of the vernier 520 is flush with the upper end face of the fixed unit 120, and the lower end face of the vernier 520 is approximately at the same height as the lower end face of the fixed unit 120.

[0077] Furthermore, the size of the vernier 520 will also differ depending on the size of the vernier caliper 500. In this case, various force measuring devices 100 of different sizes can be prepared in advance. Alternatively, the device can be pre-configured to allow variable adjustment of the height of the fixing unit 120 of the force measuring device 100. In this case, the fixing unit 120 can be further divided into an upper unit and a lower unit in advance. This can be configured to allow the upper and lower units to slide up and down, or the upper and lower units can be pre-connected using a telescopically folding elastomer or resin (corrugated resin sheet).

[0078] For example, such as Figure 7 As shown in the exploded view, the fixing unit 120 has a housing portion 130 and a circuit portion 190.

[0079] The housing portion 130 has a first cover 140 and a second cover 240, and by combining the first cover 140 and the second cover 240, a storage space is divided on the inside. The lower end face of the housing portion 130 is open.

[0080] The first cover 140 mainly constitutes the front side of the fixing unit 120.

[0081] Figure 8 This is a diagram showing the inner surface of the first cover 140.

[0082] The first cover 140 has a first base surface 150, a first upper end surface 160, a first one-end side wall surface 170, and a first other end side wall surface 180.

[0083] The first base plane 150 is a plane parallel to the XZ plane, and it is a rectangular plate that forms the front side of the fixing unit 120.

[0084] In this embodiment, a plurality of small holes are provided on the first base surface 150 to facilitate the external transmission of sound from the built-in buzzer (speaker) 193. In addition, a display panel 523 and operation buttons may be provided on the first base surface 150 in advance as needed.

[0085] Additionally, a first guide groove 151 along the X-axis direction (X direction) is provided slightly below the inner surface of the first base surface 150. Furthermore, a shallow recess for arranging a planar buzzer (speaker) 193 is provided in the approximately central region of the inner surface of the first base surface 150.

[0086] Walls are integrally erected on the upper, right, and left sides of the first base surface 150, which respectively become the first upper end surface 160, the first one-end side wall surface 170, and the first other end side wall surface 180.

[0087] The first upper surface 160 is a surface parallel to the XY plane. An opening 161 for a connection port 192 is provided on the first upper surface 160, which is used to receive the external device connector terminal 630 of the connection unit 600. Threaded holes 162 are provided on both sides of the opening 161 for the connection port.

[0088] The first end sidewall 170 is a surface parallel to the YZ plane, and it is erected on one end side of the first base surface 150.

[0089] The first other end sidewall 180 is a surface parallel to the YZ plane, and it is erected on the other end side surface of the first base surface 150. That is, the first one end sidewall 170 and the first other end sidewall 180 are opposite each other at a predetermined interval.

[0090] The second cover 240 mainly constitutes the back side of the fixing unit 120.

[0091] The second cover 240 has a second base surface 250, a second upper end surface 260, a second one-end side wall surface 270 and a second other-end side wall surface 280.

[0092] The second base surface 250 is a surface parallel to the XZ plane, and it is a rectangular plate-like body that forms the back side of the fixing unit 120. A second guide groove 251 along the X direction is provided slightly below the inner surface of the second base surface 250. A space for the circuit section 190 to be embedded is ensured slightly above the inner surface of the second base surface 250.

[0093] Walls are integrally erected on the upper, right, and left sides of the second base surface 250, which respectively become the second upper end surface 260, the second first end side wall surface 270, and the second other end side wall surface 280.

[0094] The second upper surface 260 is a surface parallel to the XY plane.

[0095] A portion of the second upper end face 260 is recessed toward the rear side (-Y direction) in a manner that receives the first upper end face 160. In order to fit into this recess, a portion of the first upper end face 160 protrudes toward the rear side (-Y direction).

[0096] The second first-end sidewall 270 is a surface parallel to the YZ plane, and it is erected on one end side of the second base surface 250. The second other-end sidewall 280 is a surface parallel to the YZ plane, and it is erected on the other end side of the second base surface 250. That is, the second first-end sidewall 270 and the second other-end sidewall 280 are opposite each other at a predetermined interval.

[0097] When the first cover 140 and the second cover 240 are joined together with their end faces matching each other, they become a shell portion 130 that divides the interior into storage spaces.

[0098] The circuit section 190 has a circuit board 191 on which electronic circuits are assembled, and a connection port 192 mounted on the circuit board 191.

[0099] As an electronic circuit, in addition to operational amplifiers and differential amplifiers that process (detect and amplify) the detection signals from pressure sensing elements 410 and 420 to serve as sensor signals, there are also comparators that compare predetermined thresholds with sensor signals.

[0100] In the comparator, a predetermined measuring force is input as a predetermined reference value. The predetermined measuring force can be set and stored either by assembling a memory or register in the circuit section 190 of the measuring force detection device 100, or it can be provided from the circuit section 550 of the vernier caliper 500 (vernier 520). In addition, a driver for a buzzer (speaker) 193 and an interface circuit for controlling the input and output of signals to the circuit section 190 on the vernier caliper 500 side are provided as needed. The circuit section 190 is located slightly above (in the +Z direction) on the inner surface side of the second cover 240, and the connection port 192 is configured to communicate with the connection port of the first upper end surface 160 through an opening 161.

[0101] Next, the movable unit 300 will be described.

[0102] Figure 9 This is a diagram showing a component unit in which pressure sensing elements 410 and 420 are installed in the movable unit 300.

[0103] The movable unit 300 includes a movable base plate 310, a sliding travel block 320, a support shaft 330, force-applying components 341 and 342, and an operating part 350.

[0104] The movable base plate 310 is rectangular and plate-shaped, designed to close the opening on the lower side of the housing 130. However, it is not necessary for the movable base plate 310 to completely close the opening on the lower side of the housing 130; for example, the area of ​​the movable base plate 310 may be smaller than the area of ​​the opening on the lower side of the housing 130. The movable base plate 310 is not fixed to the housing 130, and the movable base plate 310 can move relative to the housing 130 (fixed unit 120).

[0105] The sliding travel block 320 is erected and disposed at the center of the left and right sides (center in the X direction) of the upper side of the movable base plate 310.

[0106] The sliding travel block 320 is fixed to the movable base plate 310 in an integral manner. The sliding travel block 320 has protrusions 321 and 322, which are formed to engage with the guide grooves 151 and 251 of the first cover 140 and the second cover 240. That is, the sliding travel block 320 has a first protrusion 321 protruding towards the front side (+Y direction) on its front side (+Y direction) surface.

[0107] In addition, the sliding stroke block 320 has a second protrusion 322 on the back side (-Y direction) surface that protrudes toward the back side (-Y direction).

[0108] The first protrusion 321 is fitted into the first guide groove 151 of the first cover 140, and the second protrusion 322 is fitted into the second guide groove 251 of the second cover 240. By inserting the first protrusion 321 into the first guide groove 151 and the second protrusion 322 into the second guide groove 251, the first cover 140 and the second cover 240 are joined together in this state.

[0109] Here, Figure 10 yes Figure 1 The XX-line sectional view in the diagram.

[0110] The sliding stroke block 320 is held suspended between the first cover 140 and the second cover 240. Furthermore, the sliding stroke block 320 can be guided by the guide slots 151 and 251 to slide in the X direction.

[0111] Furthermore, this embodiment illustrates a case where grooves 151 and 251 are provided on the first cover 140 and the second cover 240 sides, and protrusions 321 and 322 are provided on the sliding stroke block 320 side. Conversely, grooves may be provided on the sliding stroke block 320 side in advance, and protrusions with raised strips may be provided on the first cover 140 and the second cover 240 sides.

[0112] The support shaft 330 is positioned to pass through the center of the sliding stroke block 320 in the X direction. The length of the support shaft 330 in the X direction is approximately equal to or slightly shorter than the length (lateral width) of the fixed unit 120 in the X direction. The support shaft 330 and the sliding stroke block 320 are not fixed together, and the sliding stroke block 320 can slide along the support shaft 330 (along the X direction).

[0113] In addition, the end faces of the first cover 140 and the second cover 240, and the other end face of the side wall 170, 180, 270 and 280, have semi-circular notches for clamping the support shaft 330.

[0114] When the first cover 140 and the second cover 240 are joined, the semi-circular notches fit together to form a circular blind hole. (This is a blind hole, but the hole could also penetrate the wall.) One end of the support shaft 330 is fitted into the blind hole, thereby fixing the support shaft 330 to the fixing unit 120. The sliding stroke block 320 is held in a suspended state by the support shaft 330, which is thus fixed. The sliding stroke block 320 can slide along the support shaft 330 and the guide groove in the X direction while suspended.

[0115] As a force-applying component 340, a first spring 341 and a second spring 342 are provided.

[0116] The first spring 341 is disposed on one end (-X direction side) of the sliding stroke block 320. The second spring 342 is disposed on the other end (+X direction side) of the sliding stroke block 320. The support shaft 330 is configured to pass through the interior of the first spring 341 and the second spring 342.

[0117] Preferably, the spring constants of the first spring 341 and the second spring 342 are the same, but this is not mandatory.

[0118] The operation unit 350 is mounted on the back side (-Y direction side) of the movable base plate 310.

[0119] The operating unit 350 is both the primary part of the force transmission unit that receives the measuring force applied by the fingers to the vernier caliper 500 or the workpiece and transmits the force to the pressure sensing elements 410 and 420 of the measuring force detection device 100, and the operating unit 350 is also a substitute operating unit that replaces the handle part 530 of the vernier 520 and is used to push and pull the vernier 520.

[0120] The operating unit 350 has a replacement hand rest 360 and an auxiliary movable plate 370.

[0121] The alternative handle 360 ​​is located on the back side (-Y direction side) of the movable base plate 310 and on the other end side (+X direction side) of the movable base plate 310, and is integrally fixed with the movable base plate 310.

[0122] The alternative hand rest 360 is shaped such that its other end side (+X direction side) has a predetermined area to facilitate pressing with fingers, and also has a recess (in this case, a shallow letter V shape) to facilitate pressing with fingers.

[0123] The alternative handle portion 360 includes an upper pressure plate portion 361 and a lower pressure plate portion 362. The upper pressure plate portion 361 is a flat plate that is slightly inclined in the Z direction to the +X direction from the movable base plate portion 310 upwards. The lower pressure plate portion 362 is located below the movable base plate portion 310. The surface of the lower pressure plate portion 362 has anti-slip unevenness.

[0124] Furthermore, when viewed from the rear side (+Y direction side), the lower pressure plate portion 362 is provided with a hole portion 363, which is designed to receive the pin 531 of the vernier 520 located on the rear side (-Y direction) of the handle portion 530 in terms of position and size.

[0125] However, in order for the movable unit 300 to move relative to the vernier 520, the size of the hole 363 needs to be slightly larger than the pin 531 on the back side of the handle portion 530 of the vernier 520. In order to allow relative movement between the hole 363 and the pin 531 in a state where they are engaged to a degree that does not fall off, for example, a resin with elasticity or softness can be provided in advance on the inner circumference of the hole 363.

[0126] Furthermore, the vernier 520 is not pushed or pulled by engaging the hole 363 of the replacement handle 360 ​​with the pin 531 of the handle 530 of the vernier 520. Therefore, the hole 363 of the replacement handle 360 ​​may not exist, or it may be a hole with a diameter sufficient to receive the pin 531 of the handle 530 of the vernier 520.

[0127] The auxiliary movable plate portion 370 is located on the back side of the movable base plate portion 310, and it is a narrow plate extending along the X direction. When the force measuring device 100 is mounted on the vernier 520 of the vernier caliper 500, the auxiliary movable plate portion 370 and the lower surface of the vernier 520 are in contact and abut against each other.

[0128] A protruding tab 532 is formed on the lower surface of the vernier 520 of the vernier caliper 500, and an insert groove is formed between the lower surface of the vernier 520 and the protruding tab 532. The auxiliary movable plate portion 370 engages with the insert groove, thereby allowing relative displacement in the X direction and supporting it from below.

[0129] Pressure sensing elements 410 and 420 are flat plate-shaped elements assembled with piezoelectric elements and resistors (piezoelectric resistors) that output pressure as a change in voltage or resistivity.

[0130] Two pressure sensing elements 410 and 420 are provided.

[0131] The first pressure sensing element 410 is configured to be pushed against one end sidewall (170, 270) inside the housing portion 130.

[0132] Additionally, the second pressure sensing element 420 is configured to be pushed against the other end sidewall (180, 280) inside the housing portion 130. The first pressure sensing element 410 and the second pressure sensing element 420 are provided with through holes for the insertion of the support shaft 330.

[0133] During the assembly of the movable unit 300, a first spring 341 and a second spring 342 are pre-installed on one end and the other end of the support shaft 330, respectively. Then, one end of the support shaft 330 is inserted into the first pressure sensing element 410 and the second pressure sensing element 420, respectively. The first cover 140 and the second cover 240 are then joined together by the sliding stroke block 320 entering between the first cover 140 and the second cover 240. This results in a state where the first spring 341 is sandwiched between the first pressure sensing element 410 and the sliding stroke block 320, and the second spring 342 is sandwiched between the second pressure sensing element 420 and the sliding stroke block 320. At this time, the first pressure sensing element 410 is pressed against one end sidewall (170, 270) by the first spring 341, and the second pressure sensing element 420 is pressed against the other end sidewall (180, 280) by the second spring 342. In this way, with the support shaft 330 as the central axis, the positional relationship of the sliding stroke block 320, the first spring 341, the second spring 342, the first pressure detection element 410, the second pressure detection element 420, one end side wall surface (170, 270) and the other end side wall surface (180, 280) is determined. Except for allowing the sliding stroke block 320 to slide, their relative positions are stably and approximately fixed.

[0134] An assembly consisting of pressure sensing elements 410 and 420 mounted on the movable unit 300 is sandwiched between the first cover 140 and the second cover 240. Figure 9 After the first cover 140 and the second cover 240 are combined, the force measuring device 100 is assembled. Figure 1 , Figure 2 The procedure for installing the force measuring device 100 onto the vernier caliper 500 has been referred to. Figures 3-6 An explanation was provided.

[0135] The operation of the force measuring device 100 is explained.

[0136] Here, the detection signal output from the first pressure sensing element 410 is designated as the first detection signal S1. The detection signal output from the second pressure sensing element 420 is designated as the second detection signal S2. Detection signals S1 and S2 are the voltage and current generated when the pressure sensing elements 410 and 420 are subjected to force.

[0137] The difference between the first detection signal S1 and the second detection signal S2 is taken as the sensor signal Sf.

[0138] Sf = S1 - S2

[0139] Consider the state where no external force from the fingers is applied to the force measuring device 100 (instead of the hand rest 360).

[0140] Now, Figure 11 This is a state in which no external force from the fingers is applied to the force measuring device 100 (replacing the hand rest 360) and the vernier 520 of the vernier caliper 500.

[0141] When no external force from the fingers is applied to the force measuring device 100 (instead of the hand rest 360), the force F1 of the first spring 341 pushing the first pressure sensing element 410 and the force F2 of the second spring 342 pushing the second pressure sensing element 420 are opposite in direction and equal in magnitude.

[0142] Therefore,

[0143] Sf = S1 - S2 = 0.

[0144] Furthermore, the first spring 341 and the second spring 342 push the sliding block 320 with opposite directions and equal magnitudes. As a result, the sliding block 320 achieves a stable state by balancing the forces at the exact midpoint between one end side wall (170, 270) and the other end side wall (180, 280).

[0145] Next, as Figure 12 As illustrated, place your fingers on the alternative hand part 360 of the force measuring device 100 and slowly push the alternative hand part 360 to one end.

[0146] When the alternative handle 360 ​​is pushed toward one end, the movable base plate 310 and the sliding travel block 320 are pushed together toward one end. As a result, the sliding travel block 320 pushes the first spring 341 toward one end, and the first spring 341 pushes the first pressure sensing element 410 and the side wall (170, 270) toward one end.

[0147] Currently, there are no components that restrict the displacement of the fixed unit 120 and the vernier 520. Therefore, when the force applied to the alternative handle 360 ​​exceeds the static resistance (static friction) of the vernier 520, the fixed unit 120 and the vernier 520 begin to slide together with the alternative handle 360 ​​(movable unit 300) toward one end. At this time, the force applied to the first pressure sensing element 410 is larger, and the force applied to the second pressure sensing element 420 is smaller, so Sf (=S1-S2)>0. However, when the vernier 520 moves, the sensor signal Sf represents a value equivalent to the sliding resistance (sliding resistance, dynamic friction) of the vernier 520.

[0148] Due to product deviations and changes over time, the static resistance and sliding resistance will vary for each vernier caliper 500. Therefore, it is preferable to pre-test by moving the vernier caliper 520 and sampling to obtain sensor signal values ​​Sf that correspond to the static resistance and sliding resistance. When setting the predetermined measuring force, it is preferable to pre-compensate for the amount of sliding resistance (or static resistance). This eliminates the sliding resistance of the vernier caliper 500 itself, allowing the setting of the true measuring force (e.g., 0.1 N) in the measuring force detection device 100 (or vernier caliper 500).

[0149] Furthermore, the method for setting the measuring force is not limited to the methods described above. For example, it is also possible to actually try to clamp the pressure gauge with the measuring jaws and sample (latch) the sensor signal Sf when the predetermined pressure (measuring pressure) is reached.

[0150] Then, the replacement handle 360 ​​is pushed, and the clamps 521 of the vernier 520 and the clamps 511 of the main scale 510 abut against the workpiece and clamp the workpiece.

[0151] After clamps 511 and 521 come into contact with the workpiece, the user's fingers further push against the alternative handle 360. At this time, since the movement of the vernier 520 is blocked by the workpiece, the movement of the fixing unit 120, which is fixed to the vernier 520, is also blocked. Therefore, with the fixing unit 120 stopped, the movable unit 300 and the alternative handle 360 ​​move relative to each other to one end. At this time, as the relative displacement of the movable unit 300 increases, the first spring 341 is compressed, and therefore the force of the first spring 341 pushing the first pressure sensing element 410 increases. On the other hand, since the second spring 342 extends, the force of the second spring 342 pushing the second pressure sensing element 420 decreases. The sensor signal Sf (=S1-S2) gradually increases, and the sensor signal Sf exceeds a value equivalent to the sliding resistance of the vernier 520 and reaches a value equivalent to the predetermined measurement force.

[0152] When the sensor signal Sf reaches a value equivalent to the predetermined measuring force, an audible sound is emitted from the buzzer (speaker) 193, informing the user that the workpiece is clamped with the predetermined measuring force. Alternatively, if the sensor signal Sf reaches a value equivalent to the predetermined measuring force, the measuring force detection device 100 sends a signal to the vernier caliper 500 to latch the measured value of the vernier caliper 500. Of course, since the force of the first spring 341 pushes the sliding travel block 320 back to the other end, the user's fingers can feel the vernier 520 being pushed into the workpiece.

[0153] The above description explains the procedure for measuring the outer diameter (outer dimension) of a workpiece, but it is understood that, as Figure 13 As shown, the same procedure is performed when measuring the inner diameter (inner dimension) of a workpiece.

[0154] Thus, according to the force measuring device 100 of this embodiment, the dimensional measurement of a workpiece can be performed using a detachable force measuring device 100 to eliminate deviations in the measuring force. Since the force measuring device 100 can be attached to and detached from the vernier caliper 500, there is no need to make the vernier caliper 500 itself large or expensive; the user can simply install the force measuring device 100 on the vernier caliper 500 as needed.

[0155] Furthermore, the present invention is not limited to the above-described embodiments, and appropriate modifications can be made without departing from the spirit of the invention.

[0156] In the above embodiments, an example is shown where the force measuring device is mounted on the vernier scale of the vernier caliper using a connecting unit; however, the connecting unit is not mandatory. For example, the fixing unit (housing part) can be directly mounted and fixed to the vernier scale of the vernier caliper.

Claims

1. A vernier caliper measurement force detecting device (100) detachably attached to a vernier (520) of a vernier caliper (500) and detecting a measurement force of the vernier caliper (500), characterized by comprising: a fixed unit (120) fixedly attached to the vernier (520) in a manner not to relatively displace with respect to the vernier (520); a movable unit (300) allowed to slightly relatively displace with respect to the fixed unit (120) in a direction parallel to a moving direction of the vernier (520); and a pressure detecting member (410, 420) disposed between the fixed unit (120) and the movable unit (300) and configured to detect a pressure applied in the direction parallel to the moving direction of the vernier (520), wherein the movable unit (300) has a substitute knob (360) disposed in the vicinity of a knob (530) of the vernier (520) so as to substitute for the knob (530) of the vernier (520) and become an operation portion for pushing and pulling the vernier (520), wherein a first elastic body and a second elastic body (341, 342) are provided between the movable unit (300) and the fixed unit (120) and apply equal forces to the movable unit (300) from both directions in the direction parallel to the moving direction of the vernier (520) in a manner that a relative position of the movable unit (300) with respect to the fixed unit (120) becomes a predetermined neutral position.

2. The vernier caliper measurement force detecting device (100) according to claim 1, characterized in that one of the fixed unit (120) and the movable unit (300) is provided with a guide groove (151, 251) or a protrusion extending in the direction parallel to the moving direction of the vernier (520), and the other of the fixed unit (120) and the movable unit (300) is provided with a protrusion (321, 322) or a groove portion fitted to the guide groove (151, 251) or the protrusion and sliding in the direction parallel to the moving direction of the vernier (520).

3. The vernier caliper measurement force detecting device (100) according to claim 1, characterized in that the fixed unit (120) has a housing portion (130) fixed to a back surface side of the vernier (520), a lower end surface of the housing portion (130) is opened so as to receive a part of the movable unit (300) and an accommodation space is partitioned in an inside of the housing portion (130), and further ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The housing portion (130) has one end side wall surface (170, 270) and the other end side wall surface (180, 280) which are surfaces perpendicular to the moving direction of the cursor (520) and which are opposed at a predetermined interval in the moving direction of the cursor (520), The pressure detecting member (410, 420) includes a first pressure detecting element (410) configured to be pushed against the one end side wall surface (170, 270) on the inside of the housing portion (130) and a second pressure detecting element (420) configured to be pushed against the other end side wall surface (180, 280) on the inside of the housing portion (130), A first elastic body (341) is provided between the first pressure detecting element (410) and the movable unit (300), A second elastic body (342) is provided between the second pressure detecting element (420) and the movable unit (300).

4. The vernier caliper measurement force detecting device (100) according to claim 3, wherein A support shaft (330) is provided inside the housing portion (130) and is fixed in a manner of being supported on the one end side wall surface (170, 270) and the other end side wall surface (180, 280) in a direction parallel to the moving direction of the cursor (520), The movable unit (300) has a through hole through which the support shaft (330) penetrates and is allowed to move in a direction parallel to the moving direction of the cursor (520) along the support shaft (330).

5. The vernier caliper measurement force detecting device (100) according to claim 3, wherein When the predetermined measurement force is detected by the pressure detecting element (410, 420), The user is informed by sound or light from the vernier caliper measurement force detecting device (100) or the vernier caliper (500).

6. The vernier caliper measurement force detecting device (100) according to claim 3, wherein When the predetermined measurement force is detected by the pressure detecting element (410, 420), the vernier caliper measurement force detecting device (100) locks the measurement value in the vernier caliper (500).

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