Measuring device

Abstract

To provide a measuring instrument with which it is possible to stabilize a measurement force with which the measurement object is pressed.SOLUTION: The measuring instrument comprises: a main scale 12 that has a first probe in contact with a measurement object W1 (outside measurement jaw 22A, inside measurement jaw 24A) and that extends in the longitudinal direction; a slider 14 that has a second probe in contact with the measurement object W1 (outside measurement jaw 22B, inside measurement jaw 24B) and that is provided to the main scale 12 so as to be movable along the longitudinal direction; an operation lever 16 that is provided to the slider 14 and is capable of tilting to one direction side and the other direction side of the longitudinal direction; and a measurement unit 18 that acquires a dimension between the first and second probes when the operation lever 16 is tilted to the one direction side to a predetermined angle of inclination and when it is titled to the other direction side to the angle of inclination.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a measuring instrument for measuring the dimensions of an object to be measured. [Background technology]

[0002] Conventionally, digital calipers (measuring instruments) have been known as calipers for measuring dimensions such as the length, width, thickness, outer diameter, and inner diameter of an object to be measured, and display the measurement value in response to the pressing of an operation button, etc., in order to reduce human errors in reading the measurement value. This digital caliper has a slider that is attached so as to be movable relative to the main scale, which serves as the measurement reference, and converts the amount of movement of this slider into an electrical signal to digitally display the measurement value.

[0003] In order to measure the dimensions of an object to be measured with high accuracy using such a digital caliper, when the pair of measuring jaws of the digital caliper are brought into contact with the object to be measured, the measuring force with which the measuring jaws press against the object to be measured must be kept constant or controlled to a desired measuring force.

[0004] Therefore, Patent Document 1 discloses a digital caliper that notifies the user by various displays or audio output whether the measuring force with which the measuring jaws in contact with the object to be measured presses the object to be measured is a predetermined value or not, thereby enabling the user to easily recognize whether the measuring force is a predetermined value or not. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-25777 Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, when using the digital caliper described in Patent Document 1, it is possible to notify the user whether the measuring force with which the measuring jaws press the object to be measured is a predetermined value, but when measuring the dimensions of the object to be measured, it is necessary to press an operation button provided on one of the digital calipers. When pressing this operation button, depending on the position of the operation button, it may be difficult to press, which changes the amount of force in the hand holding the digital caliper, resulting in a problem that the measuring force is not stable as intended by the user.

[0007] The present invention has been made in view of the above circumstances, and has as its object to provide a measuring instrument that can stabilize the measuring force that presses against the object to be measured. [Means for solving the problem]

[0008] A measuring instrument for achieving the object of the present invention comprises a main scale extending in the longitudinal direction and having a first measuring probe that abuts against the object to be measured, a slider having a second measuring probe that abuts against the object to be measured and arranged to be movable along the longitudinal direction relative to the main scale, an operating lever arranged on the slider and tiltable in one direction and the other direction in the longitudinal direction, a measuring unit that acquires the dimension between the first measuring probe and the second measuring probe when the operating lever is tilted in one direction to a predetermined tilt angle and when it is tilted in the other direction to a predetermined tilt angle, and an elastic body arranged on the operating lever that generates a resistance force against the tilting of the operating lever.

[0009] According to this measuring instrument, the second measuring element can press the measurement object with a constant measuring force every time a dimension of the measurement object is measured.

[0010] In a measuring instrument according to another aspect of the present invention, when the operating lever is tilted to the tilt angle, the elastic body generates a resistance force greater than the friction force between the main scale and the slider, thereby preventing dimensional measurement of the object from being performed when the probes are not in contact with the object.

[0011] In a measuring instrument according to another aspect of the present invention, the operating lever includes a support shaft provided on the slider, a cylindrical lever body having a first opening, a second opening, and a hollow portion, the lever body being supported so as to be tiltable in one direction and the other direction with respect to the shaft end portion with the shaft end portion of the support shaft inserted into the hollow portion through the first opening, a lid provided at the second opening opposite the first opening of the lever body, and a movable body provided movably between the lid and the shaft end portion within the hollow portion, and an elastic body is provided between the lid and the movable body within the hollow portion and urges the movable body toward the shaft end portion, thereby allowing the second measuring element to press the measurement object with a constant measuring force each time the operating lever is tilted to a predetermined tilt angle.

[0012] In a measuring instrument according to another aspect of the present invention, the movable body moves toward the lid within the hollow portion in response to tilting of the lever body relative to the support shaft, and the elastic body is compressed between the lid and the movable body, thereby generating a resistance force. This allows the second measuring element to press the measurement object with a constant measuring force each time the operating lever is tilted to a predetermined tilt angle.

[0013] In a measuring instrument according to another aspect of the present invention, the abutment portion of the movable body that abuts against the shaft end is formed to be narrower in the longitudinal direction than the shaft end, thereby allowing the abutment portion to be easily tilted on the shaft end in response to tilting of the operating lever.

[0014] In another aspect of the measuring instrument of the present invention, when an area on one side of the outer circumferential surface of the shaft end is designated as a first area, an area on the other side of the outer circumferential surface of the shaft end is designated as a second area, an area on the inner circumferential surface of the lever body facing the first area is designated as a first opposing area, and an area on the inner circumferential surface of the lever body facing the second area is designated as a second opposing area, the measuring instrument is provided with contact-type or button-type switches provided in the first area or the first opposing area and the second area or the second opposing area, one of the switches is turned on when the operating lever is tilted to a tilt angle in one direction, and the other switch is turned on when the operating lever is tilted to a tilt angle in the other direction, and the measuring unit acquires a dimension when the switch is turned on. This makes it possible to acquire the dimension of the object to be measured when the operating lever is tilted to a predetermined tilt angle.

[0015] In the measuring instrument according to another aspect of the present invention, the elastic body is a spring. [Effects of the Invention]

[0016] The present invention can stabilize the measurement force that presses the measurement object. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 2 is a front view of the digital caliper. [Figure 2] FIG. [Figure 3] FIG. [Figure 4] 10A and 10B are diagrams for explaining a measuring force when measuring the dimensions of a measurement object using a digital caliper. [Figure 5] 10A and 10B are diagrams for explaining a measuring force when measuring the dimensions of a measurement object using a digital caliper. DETAILED DESCRIPTION OF THE INVENTION

[0018] [Digital caliper configuration] FIG. 1 is a front view of a digital caliper 10, which corresponds to the measuring instrument of the present invention. The digital caliper 10 is used to measure dimensions such as the length, width, thickness, outer diameter, and inner diameter of measurement objects W1 and W2 of various shapes. Of the mutually orthogonal X, Y, and Z directions in the figure, the X direction is the longitudinal direction of the main scale 12 of the digital caliper 10, the Y direction is the lateral direction of the main scale 12, and the Z direction is the thickness direction of the main scale 12. Furthermore, one side of the X direction is the +X direction and the other side is the -X direction, and one side of the Y direction is the +Y direction and the other side is the -Y direction.

[0019] As shown in FIG. 1, the digital caliper 10 includes a main scale 12 (also called the caliper body), a slider 14 (also called the detector), an operating lever 16, a measuring unit 18, and a display unit 20.

[0020] The main scale 12 has a shape that extends in the X direction. An outer measuring jaw 22A and an inner measuring jaw 24A, which correspond to the first measuring element of the present invention, are provided at the tip of the main scale 12 on the +X direction side. The base end of the main scale 12 on the -X direction side serves as a gripping portion that is held by the user.

[0021] The outer measuring jaw 22A protrudes in the -Y direction from the tip of the main scale 12. The outer measuring jaw 22A comes into contact with the part to be measured (such as the outer surface) of the object W1 when measuring the length, width, thickness, outer diameter, etc. of the object W1.

[0022] The inner measuring jaw 24A protrudes in the +Y direction from the tip of the main scale 12. The inner measuring jaw 24A comes into contact with the part to be measured (the inner surface of a hole or recess, etc.) of the measurement object W2 when measuring the inner diameter or other dimensions of the measurement object W2.

[0023] The slider 14 is provided so as to be movable (slidable) along the X direction relative to the main scale 12. The slider 14 is provided with an outer measuring jaw 22B and an inner measuring jaw 24B, which correspond to the second measuring element of the present invention, an operating lever 16, a measuring unit 18, a display unit 20, and a setscrew 21.

[0024] The outer measuring jaw 22B protrudes in the -Y direction from the tip of the slider 14 on the +X direction side. When measuring the dimensions of the object W1, such as the length, width, thickness, and outer diameter, the outer measuring jaw 22B comes into contact with the portion to be measured of the object W1, thereby sandwiching the object W1 (portion to be measured) between the outer measuring jaw 22B and the outer measuring jaw 22A.

[0025] The inner measuring jaw 24B protrudes in the +Y direction from the tip of the slider 14. The inner measuring jaw 24B abuts against the measurement target portion of the measurement target W2 when measuring the inner diameter or other dimensions of the measurement target W2. As a result, the inner measuring jaws 24A, 24B are inscribed in the +X and -X end portions of the measurement target portion of the measurement target W2.

[0026] The operating lever 16 is provided on the underside of the slider 14 on the −Y direction side so as to be tiltable in the +X direction and the −X direction. More specifically, the operating lever 16 is provided on the underside of the slider 14 at a position where it can be tilted with a user's finger (such as the index finger or middle finger). This operating lever 16 is tilted in the +X direction or the −X direction when determining the measurement values of the dimensions of the measurement objects W1 and W2, i.e., when operating a measuring unit 18 described below.

[0027] Specifically, the operating lever 16 is tilted in the +X direction (the direction in which the outer measuring jaw 22B presses the measurement object W1) when measuring the dimension of the measurement object W1 using the outer measuring jaws 22A and 22B, and in the -X direction (the direction in which the inner measuring jaw 24B presses the measurement object W2) when measuring the dimension of the measurement object W2 using the inner measuring jaws 24A and 24B.

[0028] The measuring unit 18 uses a known encoder, transducer, etc., and acquires the dimensions of the measurement objects W1, W2 when one of switches 40, 42 in the operating lever 16 (described below) is turned on in response to tilting of the operating lever 16. The measuring unit 18 detects the amount of movement displacement of the slider 14 relative to the main scale 12 as an electrical signal, and outputs this detected amount as the measured dimension value of the measurement objects W1, W2 to the display unit 20. The movement displacement amount of the slider 14 corresponds to the dimension between the outer measuring jaws 22A, 22B when measuring the dimension of the measurement object W1, and corresponds to the dimension between the inner measuring jaws 24A, 24B when measuring the dimension of the measurement object W2.

[0029] The display unit 20 is, for example, a liquid crystal display, and displays the measured values of the dimensions of the measurement objects W1 and W2 input from the measurement unit 18. The set screw 21 is used to fix the slider 14 to the main scale 12.

[0030] [Operation lever] Fig. 2 is a front view of the operating lever 16. Fig. 3 is a cross-sectional view of the operating lever 16. As shown in Figs. 2 and 3, the operating lever 16 includes a support shaft 30, a lever body 32, a cover 34, a moving body 36, and a spring 38. Button-type or contact-type switches 40, 42 are provided inside the operating lever 16.

[0031] The support shaft 30 is provided on the underside of the base end of the slider 14 and has a shape that extends in the -Y direction. The shaft end 30a on the -Y direction side of the support shaft 30 supports the lever main body 32 via the swing shaft 31 so that the lever main body 32 can swing freely in the ±X directions.

[0032] The lever body 32 is formed in a cylindrical shape and has a first opening 32a, a second opening 32b, and a hollow portion 32c. The inner diameter of the lever body 32 is formed to be larger than the outer diameter of the support shaft 30. With the shaft end portion 30a inserted into the hollow portion 32c from the first opening 32a side, the lever body 32 is supported via the swing shaft 31 so as to be swingable in the ±X directions relative to the shaft end portion 30a.

[0033] The cover 34 is provided on the second opening 32b on the opposite side to the first opening 32a of the lever body 32. The cover 34 is a finger rest on which the user's finger rests.

[0034] The movable body 36 is movably provided in the hollow portion 32c between the shaft end portion 30a and the lid 34. The movable body 36 is biased toward the shaft end portion 30a by a spring 38, which will be described later. A block 36a is provided on the surface of the movable body 36 that faces the shaft end portion 30a.

[0035] The block 36a corresponds to the abutment portion of the present invention, and is constantly in contact with the shaft end 30a as the movable body 36 is biased by a spring 38, which will be described later. The block 36a is formed narrower than the shaft end 30a at least in the X direction. This makes it easier for the block 36a (movable body 36) to tilt in the ±X directions on the shaft end 30a in response to tilting of the operating lever 16 in the ±X directions, as will be described in detail later (see FIGS. 4 and 5).

[0036] The spring 38 corresponds to the elastic body of the present invention, and may be, for example, a coil spring. The spring 38 is provided in a compressed state between the lid 34 and the movable body 36 in the hollow portion 32c. As a result, the spring 38 constantly urges the movable body 36 toward the shaft end 30a, causing the block 36a to constantly abut against the shaft end 30a. Note that the symbol L0 in the drawing denotes the length of the spring 38 (the distance between the lid 34 and the movable body 36) before the operating lever 16 is tilted.

[0037] The biasing force F1 of the spring 38, which will be described in detail later, acts as a measuring force MF1 (see FIG. 4) that presses the outer measuring jaw 22B against the object to be measured W1 in the +X direction when the operating lever 16 is tilted in the +X direction. Conversely, when the operating lever 16 is tilted in the -X direction, the biasing force F1 of the spring 38 acts as a measuring force MF2 (see FIG. 5) that presses the inner measuring jaw 24B against the object to be measured W2 in the -X direction.

[0038] The switches 40 and 42 are provided on the inner circumferential surface of the lever main body 32 at positions facing the outer circumferential surface of the support shaft 30. Specifically, if the region on the -X direction side of the outer circumferential surface of the shaft end 30a is defined as a first region R1 and the region on the inner circumferential surface of the lever main body 32 facing the first region R1 is defined as a first opposing region OR1, the switch 40 is provided in the first opposing region OR1. Furthermore, if the region on the +X direction side of the outer circumferential surface of the shaft end 30a is defined as a second region R2 and the region on the inner circumferential surface of the lever main body 32 facing the second region R2 is defined as a second opposing region OR2, the switch 42 is provided in the second opposing region OR2.

[0039] When the operating lever 16 (lever body 32) is tilted to a predetermined tilt angle in the +X direction, the switch 40 is pressed by or comes into contact with the first region R1, and is turned on; otherwise, the switch 40 is turned off (see Figure 4).

[0040] When the operating lever 16 (lever body 32) is tilted to a predetermined tilt angle in the -X direction, the switch 42 is pressed by or comes into contact with the second region R2, and is turned on; otherwise, the switch 42 is turned off (see Figure 5).

[0041] [How digital calipers work] Fig. 4 is a diagram for explaining a measuring force MF1 when the dimension of a measurement object W1 is measured by the digital caliper 10. Fig. 5 is a diagram for explaining a measuring force MF2 when the dimension of a measurement object W2 is measured by the digital caliper 10.

[0042] As shown in Fig. 4, when measuring the dimension of a measurement object W1, the user tilts the operating lever 16 in the +X direction with the outer measuring jaws 22A and 22B each in contact with the measurement object W1 (see Fig. 1). Also, as shown in Fig. 5, when measuring the dimension of a measurement object W2, the user tilts the operating lever 16 in the -X direction with the inner measuring jaws 24A and 24B each in contact with the measurement object W2 (see Fig. 1).

[0043] In response to the tilting operation of the operating lever 16, the moving body 36 (block 36a) tilts on the shaft end 30a in the tilting direction of the operating lever 16 (+X direction side, -X direction side).

[0044] As the tilt angle of the movable body 36 increases, the movable body 36 moves relatively toward the lid 34 within the lever body 32. As a result, the distance L1 between the lid 34 and the movable body 36 becomes narrower than the distance L0, causing the spring 38 to be compressed (elastically deformed). As a result, the spring 38 generates a biasing force F1 that biases the movable body 36 toward the support shaft 30, and part of this biasing force F1 acts as a reaction force F2 (resistance force) that resists the tilt of the operating lever 16, i.e., a restoring force that restores the operating lever 16 (movable body 36) to its original position (see FIG. 3). This reaction force F2 increases as the tilt angle of the operating lever 16 increases, i.e., as the spring 38 compresses.

[0045] When the operating lever 16 is tilted in the +X direction to a predetermined tilt angle (hereinafter referred to as the predetermined tilt angle), the switch 40 is pressed by the first region R1 and turned on. As a result, the measurement unit 18 acquires the dimension of the measurement object W1 (the dimension between the outer measuring jaws 22A and 22B), and the display unit 20 displays the measured dimension value (see FIG. 4).

[0046] Conversely, when the operating lever 16 is tilted in the -X direction to a predetermined angle, the switch 42 is pressed by the second region R2 and turned on. As a result, the measurement unit 18 acquires the dimension of the measurement object W2 (the dimension between the inner measuring jaws 24A and 24B), and the display unit 20 displays the measured dimension value (see FIG. 5).

[0047] In this embodiment, if the value of the resistance F2 when the operating lever 16 is tilted in the ±X directions by a predetermined angle is defined as a "resistance threshold," then measurement and display of the dimensions of the measurement objects W1 and W2 are performed when a force equivalent to this resistance threshold is applied to the operating lever 16. Therefore, the resistance threshold becomes the measuring force MF1 with which the outer measuring jaw 22B presses the measurement object W1 in the +X direction each time the dimension of the measurement object W1 is measured, and becomes the measuring force MF2 with which the inner measuring jaw 24B presses the measurement object W2 in the -X direction each time the dimension of the measurement object W2 is measured. This allows the user to always measure the dimensions of the measurement objects W1 and W2 with constant measuring forces MF1 and MF2 simply by tilting the operating lever 16 in the ±X directions by a predetermined angle.

[0048] [Measuring forces MF1, MF2 and drag threshold] The magnitude of the measuring forces MF1 and MF2 (resistance threshold) depends on the magnitude of the biasing force F1. Therefore, the measuring forces MF1 and MF2 (resistance threshold) can be adjusted appropriately by changing the type of spring 38 (spring constant) or by changing the gap between the lid 34 and the movable body 36.

[0049] Furthermore, the drag threshold is preferably greater than the frictional force (sliding resistance) between the main scale 12 and the slider 14. This ensures that, at least when the operating lever 16 is rotated to the predetermined tilt angle, the X-direction force applied to the slider 14 via the operating lever 16 exceeds the frictional force, and the slider 14 is pressed toward the measurement objects W1 and W2 with a force greater than the frictional force. This ensures that even if a gap is generated between the measurement objects W1 and W2 and each measuring jaw (outer measuring jaw 22B, inner measuring jaw 24B), each measuring jaw can be reliably brought into contact with the measurement objects W1 and W2. In other words, the operating lever 16 is prevented from being tilted to the predetermined tilt angle when the measuring jaws are not in contact with the measurement objects W1 and W2, preventing dimensional measurement of the measurement objects W1 and W2.

[0050] [Effects of this embodiment] As described above, in this embodiment, by tilting the operating lever 16 to a predetermined tilt angle, constant measuring forces MF1, MF2 (resistance threshold) that press against the measurement objects W1, W2 can be generated and the dimensions of the measurement objects W1, W2 can be obtained. As a result, the measuring forces MF1, MF2 can be stabilized every time the dimensions of the measurement objects W1, W2 are measured.

[0051] [others] In the above embodiment, the outer measuring jaw 22B and the inner measuring jaw 24B move in the X direction integrally with the slider 14, but the inner measuring jaw 24B may be held so as to be movable in the X direction relative to the slider 14.

[0052] In the above embodiment, the switch 40 is provided in the first opposing region OR1 of the lever body 32 and the switch 42 is provided in the second opposing region OR2, but conversely, the switch 40 may be provided in the first region R1 of the support shaft 30 and the switch 42 may be provided in the second region R2.

[0053] In the above embodiment, the operating lever 16 is provided on the underside of the slider 14 on the -Y direction side, but it may also be provided on the upper surface of the slider 14 on the +Y direction side. In this case, the operating lever 16 is provided at a position on the upper surface of the slider 14 where it can be tilted by the user's thumb or the like.

[0054] In the above embodiment, switch 40 is turned on when the operating lever 16 is tilted in the +X direction to a predetermined tilt angle, and conversely, switch 42 is turned on when the operating lever 16 is tilted in the -X direction to a predetermined tilt angle, but the present invention is not limited to this. For example, if switches 40 and 42 are provided in a position on the +Y direction side of the oscillation shaft 31, switch 42 is turned on when the operating lever 16 is tilted in the +X direction to a predetermined tilt angle, and conversely, switch 40 is turned on when the operating lever 16 is tilted in the -X direction to a predetermined tilt angle.

[0055] In the above embodiment, a coil spring is used as the spring 38, but various springs capable of generating the biasing force F1 by compression, such as a leaf spring, may also be used. Also, instead of providing the spring 38 inside the hollow portion 32c, for example, a torsion spring (elastic body) may be provided on the swing shaft 31, and this torsion spring may generate a resistance force F2 that resists the tilting of the operating lever 16. Furthermore, in the above embodiment, various springs are used as examples of the elastic body of the present invention, but various elastic bodies capable of generating the above-mentioned resistance force F2 (restoring force) by elastic deformation, such as rubber, may also be used.

[0056] In the above embodiment, the measurement results of the dimensions of the measurement objects W1 and W2 acquired by the measurement unit 18 are displayed on the display unit 20, but the measurement results may also be output as audio from a speaker (not shown). Also, the measurement results of the dimensions may be output to an external device (such as a monitor, printer, storage, or server).

[0057] In the above embodiment, the digital caliper 10 has been used as an example for explanation, but the present invention can be applied to various digital measuring instruments such as micrometers that acquire the dimension between a first measuring probe and a second measuring probe of various shapes in response to a user's measurement start operation. [Explanation of symbols]

[0058] 10 digital caliper, 12 main scale, 14 slider, 16 operating lever, 18 measuring unit, 20 display unit, 21 setscrew, 22A, 22B outer measuring jaws, 24A, 24B inner measuring jaws, 30 support shaft, 30a shaft end, 31 swing shaft, 32 lever body, 32a first opening, 32b second opening, 32c hollow portion, 34 cover, 36 moving body, 36a block, 38 spring, 40, 42 switch, F1 biasing force, F2 resistance force, MF1, MF2 measuring force, OR1 first opposing area, OR2 second opposing area, R1 first area, R2 second area, W1, W2 measuring object

Claims

[Claim 1] a main scale extending in the longitudinal direction and having a first probe that contacts the object to be measured; a slider having a second probe that contacts the object to be measured and that is provided so as to be movable along the longitudinal direction relative to the main scale; an operating lever provided on the slider and tiltable in one direction and the other direction in the longitudinal direction; a measuring unit that acquires a dimension between the first probe and the second probe when the operating lever is tilted in the one direction up to a predetermined tilt angle and when the operating lever is tilted in the other direction up to the tilt angle; a resistance generating unit that generates a resistance against the tilting of the operating lever; A measuring instrument comprising:

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