Shape measurement unit

Abstract

A shape measurement unit S100 comprises a cylindrical housing 31 that is to be mounted on a tool holding part 13 of a machine tool 10, an emission part 33 that is provided inside the housing 31 and emits measurement light that is irradiated at a measurement target, a light reception part 35 that is provided inside the housing 31 and receives reflection light that is measurement light that has been reflected by the measurement target, and a shutter device 40 that has an opening / closing mechanism 41 that opens / closes an opening 31a in the housing 31 through which the measurement light and the reflection light pass.

Description

Shape measurement unit

[0001] The present invention relates to a shape measurement unit.

[0002] 2. Description of the Related Art Conventionally, a technique for measuring the shape of a workpiece by using a measurement probe attached to a machine tool is known (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2019-209466

[0004] However, there is a problem that floating particles such as coolant mist are floating in the air in the room where the machine tool is installed, and these floating particles adhere to the measuring equipment, reducing the measurement accuracy.

[0005] SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to provide a shape measuring unit that can prevent a decrease in measurement accuracy due to the adhesion of floating matter.

[0006] In one aspect of the present invention, a shape measurement unit is provided, comprising: a cylindrical housing attached to a tool holding portion of a machine tool; an emission portion disposed within the housing for emitting measurement light to be irradiated onto an object to be measured; a light receiving portion disposed within the housing for receiving reflected light of the measurement light reflected by the object to be measured; and a shutter device having an opening / closing mechanism for opening and closing an opening in the housing through which the measurement light and the reflected light pass.

[0007] The present invention has the effect of providing a shape measuring unit that can prevent a decrease in measurement accuracy due to adhesion of floating matter.

[0008] It is a figure which shows typically the form measuring unit and the machine tool of one embodiment of this invention. It is a block diagram which shows the structure of the machine tool and the form measuring unit. It is a sectional view which shows the structure of the form measuring unit. It is a figure which shows typically the shutter mechanism. It is a flowchart which shows an example of the operation control of the shutter device.

[0009] Fig. 1 is a diagram schematically showing a shape measuring unit and a machine tool according to one embodiment of the present invention. Fig. 2 is a block diagram showing the configuration of the machine tool and the shape measuring unit. The up and down direction in Fig. 1 corresponds to the vertical direction (Z-axis direction).

[0010] The shape measuring unit S100 of this embodiment is a unit for measuring the shape of a workpiece W in a non-contact manner using triangulation. The shape measuring unit S100 is attached to a machine tool 10 as shown in FIG. 1 . The specific structure of the shape measuring unit S100 will be described later. The shape measuring unit S100 may be attached in any direction and is not limited to the vertical direction.

[0011] A key feature of the shape measurement unit S100 is that a shutter device that opens and closes the opening of the housing is provided in the housing in which the light emitting unit and the light receiving unit are arranged. With this configuration, by closing the shutter device when shape measurement is not being performed, it is possible to prevent floating particles such as mist from adhering to the measuring device.

[0012] 1, the machine tool 10 includes a stage 11, a moving mechanism 12, a tool holding unit 13, a tool driving mechanism 14, a control device 20, and a communication unit 25 (see FIG. 2). The machine tool 10 is, for example, a machining center.

[0013] The stage 11 has a mounting surface 11a on which a workpiece W, which is an object to be measured, is placed. The stage 11 is configured to be movable, for example, in directions along an X-axis and a Y-axis that are perpendicular to each other.

[0014] The moving mechanism 12 has a drive source (not shown) and moves the stage 11. The moving mechanism 12 moves the stage 11 to a predetermined position in accordance with a control signal from the control device 20. The moving mechanism 12 moves the shape measuring unit S100 and the workpiece W relative to each other. As an example, the moving mechanism 12 moves the shape measuring unit S100 and the workpiece W relative to each other so that the shape measuring unit S100 moves relative to the workpiece W along a path set based on the three-dimensional data of the workpiece W and the type of shape measurement.

[0015] The tool holder 13 is a component to which multiple types of tools are interchangeably attached. One example of the tool holder 13 is a shank that holds a columnar or cylindrical member. Not only tools but also the shape measuring unit S100 can be attached to the tool holder 13.

[0016] The work of attaching the tool and the shape measuring unit S100 to the tool holding unit 13 may be performed by an operator or by an automatic tool changer. The automatic tool changer is a machine that automatically attaches any tool from among a plurality of tools held in a magazine to the tool holding unit 13. The automatic tool changer attaches the shape measuring unit S100 of this embodiment to the tool holding unit 13 in addition to the tool.

[0017] The tool driving mechanism 14 has a driving source (not shown), such as a motor. The tool driving mechanism 14 rotates the tool holding part 13 around a rotation axis in the Z-axis direction using power from the driving source. The operation of the tool driving mechanism 14 is controlled by the control device 20.

[0018] The control device 20 has a CPU (Central Processing Unit), RAM (Random Access Memory), and ROM (Read Only Memory). The CPU reads various processing programs stored in the ROM and executes various processes. The RAM is used as a working area for the CPU and temporarily stores input data and processing results generated when the processing programs are executed. The ROM is a storage unit configured, for example, with non-volatile semiconductor memory. The ROM stores various programs that can be executed by the CPU, data used when the programs are executed, and data of processing results generated by arithmetic processing by the CPU.

[0019] The control device 20 controls the operations of the moving mechanism 12 and the tool driving mechanism 14. The control device 20 is communicatively connected to the shape measuring unit S100 via a communication unit 25 (see FIG. 2).

[0020] The control device 20 transmits a start notification to the shape measuring unit S100 indicating that shape measurement of the workpiece W will begin. The control device 20 also transmits an end notification to the shape measuring unit S100 indicating that shape measurement of the workpiece W has ended. The control device 20 may also transmit a notification to the shape measuring unit S100 indicating that the shape measuring unit S100 has been detached from the tool holding portion 13. In this embodiment, such a notification is used as a trigger for controlling the operation of the shape measuring unit S100. The "start notification" is, for example, a notification indicating that a series of measurement operations will begin, in which the shape measuring unit S100 is moved relative to the workpiece W along a predetermined path to measure the shape at multiple locations on the workpiece W. The "end notification" is, for example, a notification indicating that the series of measurement operations has ended.

[0021] (Regarding the Shape Measuring Unit S100) Fig. 3 is a cross-sectional view showing the configuration of the shape measuring unit. Fig. 4 is a diagram schematically showing a shutter mechanism. As shown in Figs. 3 and 4, the shape measuring unit S100 has a housing 31, an emitting unit 33, a light receiving unit 35, a first cover glass 37, a second cover glass 38, and a shutter device 40. As components not shown in Figs. 3 and 4, the shape measuring unit S100 has a communication module 55 and a control unit 50 as shown in Fig. 2.

[0022] The housing 31 is cylindrical, and has an opening 31a formed at its lower end as shown in FIG. 3 . As will be described later, the opening 31a is a portion through which the measurement light irradiated toward the workpiece W and the light reflected by the workpiece W pass. The housing 31 is, for example, a cylinder. A base end 31b on the outer periphery of the housing 31 can be attached to the tool holding portion 13 of the machine tool 10. In this example, the housing 31 is formed from a single member. The material of the housing 31 is, for example, metal. In this specification, the term "cylindrical" is not necessarily limited to a shape in which the length of the cylinder is longer than the width of the cylinder.

[0023] The emission unit 33 is disposed within the housing 31. The emission unit 33 emits measurement light that is irradiated toward the workpiece W. As an example, the emission unit 33 emits laser light. In this example, the emission unit 33 is disposed near the opening 31 a. Specifically, in this example, the emission unit 33 is disposed in an orientation such that the measurement light is parallel to the extension direction of the housing 31. The emission unit 33 may be fixed to an inner wall of the housing 31, or may be supported by a support member (not shown) fixed to the housing 31.

[0024] The light receiving unit 35 receives the measurement light reflected by the workpiece W. The light receiving unit 35 has a light receiving lens 35a and a light receiving element 35b. The light receiving lens 35a collects light toward the light receiving element 35b. The light receiving element 35b is disposed so that the light receiving surface is inclined with respect to the optical axis of the light receiving lens 35a.

[0025] The first cover glass 37 is provided near the position where the measurement light is emitted from the emission unit 33. The second cover glass 38 is provided near the position where the light receiving unit 35 receives the reflected light. These cover glasses are protective members for optical components such as the emission unit 33 and the light receiving unit 35. One or both of the first cover glass 37 and the second cover glass 38 may be omitted.

[0026] (Shutter Device 40) As shown in Fig. 3, the shutter device 40 has an opening / closing mechanism 41 and a drive mechanism 45. The shutter device 40 is attached to the housing 31, for example.

[0027] The opening / closing mechanism 41 is a mechanism that opens and closes the opening 31a of the housing 31. Specifically, the opening / closing mechanism 41 has a frame 42 and a plurality of diaphragm blades 43. As shown in FIG. 4 , the frame 42 is, for example, ring-shaped. The frame 42 is fixed to an end of the housing 31.

[0028] The multiple diaphragm blades 43 are arranged along the circumferential direction of the frame 42 (the same as the circumferential direction of the opening 31a of the housing 31). The multiple diaphragm blades 43 are arranged so that an opening 43a is formed in the center of the multiple diaphragm blades 43. The multiple diaphragm blades 43 are arranged to be operable so as to be in an open state that exposes the opening 31a of the housing 31 and in a closed state that closes the opening 31a. As an example, the multiple diaphragm blades 43 are arranged so that the opening 43a is completely closed in the closed state, which is a so-called zero aperture iris. In other words, the multiple diaphragm blades 43 are configured so that the central opening is blocked in the closed state.

[0029] The drive mechanism 45 (see FIG. 3 ) is a mechanism that operates the opening / closing mechanism 41 and is disposed inside the housing 31 in this embodiment. The drive mechanism 45 has a drive source (not shown), which is, for example, an actuator such as a motor, and a transmission mechanism (not shown) that transmits the power of the drive source to the aperture blades 43 of the opening / closing mechanism 41. The drive mechanism 45 operates the drive source to move the aperture blades 43 and change the size of the opening 43 a. Although not shown, a battery that supplies power to operate the drive mechanism 45 may be disposed inside the housing 31. This battery may also supply power to the control unit 50 and the communication module 55.

[0030] There is no particular limitation to the specific structure by which the drive mechanism 45 moves the plurality of diaphragm blades 43. The drive mechanism 45 may be configured to move the plurality of diaphragm blades 43, for example, by rotating a movable plate (not shown) that is rotatably provided in the circumferential direction relative to the frame 42.

[0031] 2 again, the communication module 55 is a module for wirelessly communicating with an external device. The communication module 55 is disposed inside the housing 31, for example.

[0032] The control unit 50 (see FIG. 2) has a CPU (Central Processing Unit), RAM (Random Access Memory), and ROM (Read Only Memory). The basic functions of the CPU, RAM, and ROM are similar to those of the control device 20 described above, and therefore a description thereof will be omitted. The control unit 50 is disposed, for example, inside the housing 31.

[0033] The control unit 50 controls the operations of the emission unit 33 and the shutter device 40. The control unit 50 transmits the detection result of the light receiving unit 35 (i.e., the electrical signal output from the light receiving unit 35) to the outside via the communication module 55. The control unit 50 transmits the detection result to a computer (not shown) that is a shape measuring machine. The control unit 50 may also transmit the detection result to the machine tool 10.

[0034] The control unit 50 receives various notifications from the machine tool 10 via the communication module 55. The control unit 50 also receives various notifications from other devices communicatively connected to the machine tool 10 via the communication module 55. The control unit 50 receives various notifications, for example, from an automatic tool changer capable of holding the shape measuring unit S100. The "various notifications" are, for example, notifications indicating that the shape measuring unit S100 has been removed from the tool holding unit 13.

[0035] (Operation Control of Shutter Device) The shutter device 40 of this embodiment prevents floating matter such as mist from adhering to components that make up the optical system of the shape measuring unit S100. As an example, it is preferable that the shutter device 40 be closed when the shape measuring unit S100 is not performing shape measurement. To achieve this, the control unit 50 controls the drive mechanism 45 to close the opening / closing mechanism 41 after shape measurement of the workpiece W is completed.

[0036] The control unit 50 may control the operation of the shutter device 40 in conjunction with the operation of the machine tool 10. This will be described in detail below with reference to Fig. 5. Fig. 5 is a flowchart showing an example of the operation control of the shutter device. In the initial state of Fig. 5, the shutter device 40 of the shape measuring unit S100 is closed.

[0037] First, in step S1, the control device 20 of the machine tool 10 transmits a start notification indicating that measurement of the shape of the workpiece W will start to the shape measuring unit S100.

[0038] Next, in step S2, the control unit 50 of the shape measuring unit S100 controls the drive mechanism 45 to open the opening / closing mechanism 41 of the shutter device 40 in response to receiving the start notification from the machine tool 10. As a result, the opening / closing mechanism 41 opens, the opening 31a of the housing 31 is exposed, and the shape measuring unit S100 becomes able to measure the workpiece W.

[0039] Next, in step S3, machine tool 10 starts measuring the shape of workpiece W. When the shape measurement of workpiece W is completed, in step S4, control device 20 of machine tool 10 transmits an end notification indicating that the shape measurement of workpiece W has been completed to shape measuring unit S100.

[0040] Next, in step S5, in response to receiving the end notification from machine tool 10, control unit 50 controls drive mechanism 45 to close opening / closing mechanism 41.

[0041] Through the above-described series of steps, in the shape measuring unit S100, the shutter device 40 opens when the shape of the workpiece W is measured, and closes after the shape measurement is completed. With this configuration, there is no need for an operator to manually operate the shape measuring unit S100 to open and close the shutter device 40. Furthermore, the shutter device 40 can be opened and closed at appropriate timing in accordance with the operation of the machine tool 10.

[0042] (Effects of Shape Measuring Unit S100) As described above, the shape measuring unit S100 of this embodiment is provided with the shutter device 40 that opens and closes the opening 31a of the housing 31, and closing this shutter device 40 can prevent floating particles such as mist from adhering to the measuring equipment. In particular, the shape measuring unit S100 of this embodiment has a control unit 50 and a drive mechanism 45, and the drive mechanism 45 is controlled so that the opening and closing mechanism closes after measurement of the shape of the measurement target of the workpiece W is completed. Therefore, there is no need for an operator to manually close the shutter device 40.

[0043] (Modifications) In the above description, the shutter device 40 has been described as having a plurality of aperture blades 43 arranged in the circumferential direction of the frame 42, but the shutter device is not limited to such a configuration. The shutter device may be a plain shutter in which a target portion is opened and closed by the movement of a plurality of blades arranged approximately parallel to one another.

[0044] Although the flowchart in FIG. 5 illustrates an example in which both the start notification and the end notification are transmitted to the shape measurement unit S100, only one of them may be transmitted.

[0045] The timing at which the shape measuring unit S100 closes the shutter device 40 is not limited to the timing at which the end notification is received as shown in FIG. 5 . The control unit 50 may control the drive mechanism 45 to close the opening / closing mechanism 41 in response to receiving a notification from the machine tool 10 or another device (e.g., an automatic tool changer) communicatively connected to the machine tool indicating that the shape measuring unit S100 has been removed from the tool holding unit 13. With this configuration, the opening 31a of the housing 31 can be closed by the shutter device 40 after the shape measuring unit S100 has been used, thereby effectively preventing the adhesion of floating matter when the shape measuring unit S100 is not attached to the machine tool 10. The control unit 50 may also control the drive mechanism 45 to open the opening / closing mechanism 41 while receiving an ON signal indicating that the machine tool 10 is operating via the communication module 55, and control the drive mechanism 45 to close the opening / closing mechanism 41 in response to the fact that the ON signal indicating that the machine tool 10 is operating is no longer received via the communication module 55. The ON signal is transmitted from the machine tool 10, for example, at predetermined time intervals.

[0046] Furthermore, when the shutter device 40 has a drive mechanism 45 that operates the opening / closing mechanism 41 as described above, a shape measurement unit according to one embodiment of the present invention may be configured as follows. Specifically, the opening / closing mechanism 41 may be configured to close the opening in an initial state (meaning a normal state in which shape measurement is not being performed), and the control unit 50 may control the drive mechanism 45 to open the opening in response to receiving a control signal to open the opening. The "control signal to open the opening" may be transmitted from any device capable of communicating with the control unit 50. For example, when the drive mechanism 45 does not have a function to close the opening / closing mechanism 41 but has a mechanism to open it, the opening / closing mechanism 41 may be configured to close the opening in an initial state and to open it when a force is applied from the drive mechanism 45.

[0047] In another embodiment of the shape measurement unit of the present invention, the opening / closing mechanism 41 includes a plurality of aperture blades 43 and a biasing member (not shown). The biasing member, e.g., a spring, applies a biasing force to one or more aperture blades 43 in a direction to close the aperture blades 43. As a result, the aperture blades 43 are configured to close due to the biasing force when no external force is applied. In other words, with this configuration, when the drive mechanism 45 finishes opening the opening / closing mechanism 41, the biasing force of the biasing member moves the aperture blades 43, causing them to close. With this configuration, for example, the drive mechanism 45 does not actively close the aperture blades 43, but the biasing member acts to close the aperture blades 43. This simplifies the configuration and eliminates the need for complex operational control. Even with this configuration, the control unit 50 may control the drive mechanism 45 to close the opening / closing mechanism 41 in response to the absence of an ON signal indicating that the machine tool 10 is operating. Specifically, the control unit 50 controls the drive mechanism 45 to release the state in which the plurality of aperture blades 43 are maintained in the open state, thereby causing the plurality of aperture blades 43 to close due to the action of the biasing member, thereby preventing floating particles from adhering to the measuring device.

[0048] The present invention has been described above using embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. For example, all or part of the device can be configured by functionally or physically distributing or integrating in any unit. Furthermore, new embodiments resulting from any combination of multiple embodiments are also included in the embodiments of the present invention. The effects of the new embodiments resulting from the combination also have the effects of the original embodiments.

[0049] This application discloses the following invention: (Supplementary Note 1) A shape measurement unit including: a cylindrical housing attached to a tool holding section of a machine tool, an emission section disposed within the housing that emits measurement light to be irradiated onto a measurement object, a light receiving section disposed within the housing that receives light reflected from the measurement object, and a shutter device having an opening / closing mechanism that opens and closes an opening in the housing through which the measurement light and the reflected light pass.

[0050] (Appendix 2) The shape measurement unit described in Appendix 1, wherein the opening / closing mechanism has a plurality of aperture blades arranged along the circumferential direction of the opening and operable to be in an open state that exposes the opening and in a closed state that closes the opening.

[0051] (Appendix 3) A shape measurement unit as described in Appendix 1 or 2, wherein the shutter device has a drive mechanism that operates the opening and closing mechanism, and further includes a control unit that controls the operation of the drive mechanism, and the control unit controls the drive mechanism so that the opening and closing mechanism closes after shape measurement of the object to be measured is completed.

[0052] (Appendix 4) A shape measurement unit as described in Appendix 3, further comprising a communication module capable of communicating with the machine tool, wherein the control unit controls the drive mechanism to close the opening / closing mechanism in response to receiving a completion notification from the machine tool via the communication module indicating that the shape measurement has been completed, or in response to no longer receiving an ON signal via the communication module indicating that the machine tool is operating.

[0053] (Appendix 5) A shape measurement unit as described in Appendix 3, further comprising a communication module capable of communicating with the machine tool, wherein the control unit controls the drive mechanism to open the opening / closing mechanism in response to receiving a start notification from the machine tool via the communication module indicating that the shape measurement is about to begin.

[0054] (Appendix 6) A shape measuring unit as described in Appendix 3, wherein the control unit controls the drive mechanism to close the opening / closing mechanism in response to receiving a notification from the machine tool or another device connected to the machine tool indicating that the shape measuring unit has been removed from the tool holding unit.

[0055] (Appendix 7) The shutter device has a drive mechanism that operates the opening / closing mechanism, which closes the opening in an initial state, and further includes a control unit that controls the operation of the drive mechanism, and the control unit controls the drive mechanism to open the opening / closing mechanism in response to receiving a control signal to open the opening.The shape measurement unit described in Appendix 1.

[0056] (Appendix 8) The shape measurement unit described in Appendix 7, wherein the opening / closing mechanism has a plurality of aperture blades that can operate to be in an open state that exposes the opening and a closed state that closes the opening, and a biasing member that applies a biasing force to one or more of the aperture blades in a direction that closes the plurality of aperture blades, and is configured so that when the operation of opening the opening / closing mechanism by the drive mechanism is completed, the biasing force of the biasing member moves the plurality of aperture blades to close the plurality of aperture blades.

[0057] (Appendix 9) The shape measurement unit described in Appendix 2, wherein the housing is cylindrical and the plurality of aperture blades are configured such that, when closed, central openings of the plurality of aperture blades are blocked.

[0058] REFERENCE SIGNS LIST 10 Machine tool 11 Stage 11a Placement surface 12 Moving mechanism 13 Tool holding section 14 Tool driving mechanism 20 Control device 25 Communication section 31 Housing 31a Opening 31b Base end 33 Emission section 35 Light receiving section 35a Light receiving lens 35b Light receiving element 37 First cover glass 38 Second cover glass 40 Shutter device 41 Opening / closing mechanism 42 Frame 43 Diaphragm blade 43a Opening 45 Driving mechanism 50 Control section 55 Communication module S5 Step S100 Shape measuring unit W Workpiece

Claims

1. A shape measurement unit comprising: a cylindrical housing attached to a tool holding part of a machine tool; an emission part disposed within the housing for emitting measurement light to be irradiated onto an object to be measured; a light receiving part disposed within the housing for receiving light reflected from the object to be measured; and a shutter device having an opening / closing mechanism for opening and closing an opening in the housing through which the measurement light and the reflected light pass.

2. The shape measurement unit according to claim 1, wherein the opening / closing mechanism has a plurality of aperture blades arranged along the circumferential direction of the opening and operable to be in an open state that exposes the opening and in a closed state that closes the opening.

3. A shape measurement unit as described in claim 1 or 2, wherein the shutter device has a drive mechanism that operates the opening and closing mechanism, and further comprises a control unit that controls the operation of the drive mechanism, and the control unit controls the drive mechanism so that the opening and closing mechanism closes after shape measurement of the object to be measured is completed.

4. A shape measurement unit as described in claim 3, further comprising a communication module capable of communicating with the machine tool, wherein the control unit controls the drive mechanism to close the opening / closing mechanism in response to receiving a completion notification from the machine tool via the communication module indicating that the shape measurement has been completed, or in response to no longer receiving an ON signal via the communication module indicating that the machine tool is operating.

5. A shape measurement unit as described in claim 3, further comprising a communication module capable of communicating with the machine tool, wherein the control unit controls the drive mechanism to open the opening / closing mechanism in response to receiving a start notification from the machine tool via the communication module indicating that the shape measurement is about to begin.

6. A shape measuring unit as described in claim 3, wherein the control unit controls the drive mechanism to close the opening / closing mechanism in response to receiving a notification from the machine tool or another device connected to the machine tool indicating that the shape measuring unit has been removed from the tool holding unit.

7. The shape measurement unit of claim 1, wherein the shutter device has a drive mechanism that operates the opening / closing mechanism, which closes the opening in an initial state, and further comprises a control unit that controls the operation of the drive mechanism, and the control unit controls the drive mechanism to open the opening / closing mechanism in response to receiving a control signal to open the opening.

8. The shape measurement unit described in claim 7, wherein the opening / closing mechanism has a plurality of aperture blades operable to be in an open state that exposes the opening and in a closed state that closes the opening, and a biasing member that applies a biasing force to one or more of the aperture blades in a direction that closes the plurality of aperture blades, and is configured so that when the operation of the drive mechanism to open the opening / closing mechanism is completed, the biasing force of the biasing member moves the plurality of aperture blades to close the plurality of aperture blades.

9. The housing is cylindrical, and the plurality of aperture blades are configured such that, when closed, the central openings of the plurality of aperture blades are blocked. The shape measuring unit according to claim 2 .

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