JPH02109661A - Contact detection device - Google Patents

Abstract

PURPOSE:To increase repeating accuracy and to reduce malfunction by forming the outer peripheral face of the bulging part of a contact body in the spherical face opposed to the inside face of a guide with small gap. CONSTITUTION:The outer periphery of the bulging part 21a of a locator 21 has its center X on the center axial line of a probe 18 and is taken as the spherical face that the diameter (d) thereof is slightly smaller than the inner diameter of a guide 15. So that the outer peripheral face B of the bulging part 21a is opposed over the whole periphery to the inside face 15a of the guide 15 with a small gap. And yet this state is not changed even if the bulging part 21a is inclined to the orthogonal direction to the shaft of the guide 15. Accordingly the bulging part 21a is difficult to bite at this place to the inside face 15a of the guide 15 and its malfunction is less. Also due to the gap between the outer peripheral face B of the bulging part 21a and the inside face 15a of the guide 15 being small, the movement of a contact body 17 is only about turning and constant and so the repeating accuracy is high.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a contact detection device used for automatic centering, automatic measurement, automatic tool length measurement, etc. of a machine tool.

``Prior Art'' Conventionally, as a contact detection device used for automatic measurement of a machine tool, a three-point support system as shown in FIGS. 4 to 6 is known. This device will be described below. In FIG. 4, a contact 1 is provided with three support rods 2 extending from its base. A movable cylindrical body 3 having electrical conductivity is provided at the tip of each support rod 2, and this is biased by a spring or the like, as shown in FIG.
Each is pressed against two fixed cylindrical bodies 4 having electrical conductivity. A total of three fixed cylinder bodies 4 are electrically connected as shown in FIG. 6, and the output terminals T + ,
T! is provided.

When the object to be measured is not in contact with the tip of the contactor 1, the three movable cylindrical bodies 3 are in contact with the two fixed cylindrical bodies 4, respectively, as shown in FIG.

Therefore, the two adjacent fixed cylindrical bodies 4 are electrically connected via the movable cylindrical body 3, and the sixth
The circuit shown in the figure is closed as a whole, with output terminals T,,T
, there is electrical continuity between them.

Now, when the object to be measured comes into contact with the tip of contact I,
is displaced and the movable cylindrical body 3 separates from the fixed cylindrical body 4 at one or more locations, there will be no continuity between the output terminals T 1 , , T 2 . Then, when the object to be measured leaves the tip of the contact 1, the movable cylindrical body 3 returns to its original position, and the state where there is continuity between the output terminals T, , T, is restored again.

As described above, when the object to be measured comes into contact with the tip of the contactor 1, T1. Since there is no conduction between T, contact between the object to be measured and the contact can be detected.

However, the three-point support type contact detection device described above,
It had problems that should be improved as shown below.

(1) In the above-mentioned contact detection device, the contact of the object to be measured with the contact is detected only after the contact has been displaced by a predetermined value. The object to be measured moves a small distance until it is detected (hereinafter, this distance will be referred to as the "working distance"). When the object to be measured approaches the contact from a direction perpendicular to the axis of the contact, the above-mentioned working distance differs depending on the direction in which the object to be measured approaches the contact. This is because the configuration of the main part is not axially symmetrical with respect to the axis of the contact 1 when it is not displaced, and the amount of displacement of the contact 1 and the amount of displacement of the movable cylindrical body 3.3. This is because the relationship differs depending on the direction in which the contact i is displaced. Specifically, when the above-mentioned working distance is expressed using the angle with respect to the axis of the contact as a reference, it becomes as shown in FIG. 7. Therefore, it was necessary to measure the above-mentioned working distance in advance and correct the measured value based on the measured value. However, this correction is troublesome, and if it is not known from which direction the contact was made, it is difficult to make a complete correction, reducing measurement accuracy.

(2) The joint between the movable cylindrical body 3 and the fixed cylindrical body 4 serves as both an electrical contact point and a fulcrum for the displacement of the contact l, so that electrical stress and mechanical stress are concentrated in one place. Due to the concentration, there were many failures and short lifespan.

Therefore, a device as shown in FIG. 8 was proposed as a solution to the problems of the three-point support type contact detection device. This will be explained below.

5 is a housing. This housing 5 has an inner surface 6 having a circular cross section.
a, an inner end surface 6b perpendicular to the inner surface 6a, and an opening 6c provided in a wall forming the inner end surface 6b.
is provided. In the vicinity of the opening 6c of the guide 6, a disk-shaped protruding portion 8 is attached to the contact 7, which is entirely rod-shaped and has a spherical portion 7a at one end, so as to protrude perpendicularly to the axis of the contact 7. The provided contact body 9 is arranged such that the projecting portion 8 is inside the guide 6 and the spherical portion 7a side of the contact 7 is projected outside from the opening 6c of the guide 6. Further, in the housing 5, a round bar-shaped movable body IO is located on the opposite side from the spherical part 7a of the contactor 7 and whose central axis coincides with the central axis of the inner surface 6a of the guide 6. It is mounted movably in the axial direction by a linear bearing 11. A sphere 12 is interposed between the movable body 10 and the contact body 9.

Further, a spring 1 is attached to the housing 5 so as to press the end surface of the projecting portion 8 of the contact body 9 against the inner end surface 6b of the guide 6 via the sphere 12 by pushing the movable body 10 in the direction of the contact body 9.
3 is installed. Furthermore, although not shown, the housing 5 is provided with a switch that detects movement of the moving body 10 and issues a signal.

Here, the outer circumferential surface of the protruding part 8 of the contact body 9 is cylindrical, and its outer diameter is smaller than the inner diameter of the guide, so that the protruding part 8 is perpendicular to the axis of the guide 6. When it is,
The outer peripheral surface of the projecting portion 8 faces the inner surface 6a of the guide 6 with a predetermined gap therebetween. Further, the shape of the projecting portion 8 of the contact body 9 and the shape of the surface in contact with the sphere 12 are axially symmetrical with respect to the axis of the contactor 7, and the shape of the surface of the movable body 10 in contact with the sphere I2 is as follows. It is axially symmetrical with respect to the axis of the guide 6.

When the object to be measured is not in contact with the contact 7,
Due to the bias of the spring described above, the end surface of the projecting portion 8 of the contact body 9 contacts the inner end surface 6b of the guide 6 in an annular shape.

Now, when the object to be measured approaches from the direction perpendicular to the axis of the contactor 7 and comes into contact with the spherical part 7a of the contactor 7, the contactor 9 will be in contact with the object to be measured at the end surface of the overhanging part 8. The guide 6 is rotated so that only one side remains and the other parts move away from the inner end surface 6b of the guide 6. As a result, the moving body 10 moves to the sphere 12.
is moved to the right in FIG. Due to this movement of the moving body 1 (1), the switch emits a signal, and contact with the contact 7 of the object to be measured is detected.

Here, in the above contact detection device, the shapes of the components that determine the relationship between the displacement amount of the contactor 7 and the movement amount of the movable body 10 are all aligned with the axis of the guide 6 when the object to be measured is not in contact with it. Because it is axially symmetrical, when the object to be measured moves in a direction perpendicular to the contact 7, the relationship between the amount of displacement of the contact 7 and the amount of movement of the moving body IQ is as follows: 7 remains constant even if the direction of approach changes. Therefore, the above-mentioned working distance does not vary depending on the direction in which the object to be measured approaches the contactor 7.

The contact detection device described above and shown in FIG. 8 has the above-mentioned working distance that does not vary depending on the direction and the electrical contact does not also serve as a mechanical fulcrum, and is different from the above-mentioned three-point support system. It was an excellent solution to the problem.

"Problems to be Solved by the Invention" However, the device shown in FIG. 8 also had problems that required further improvement, as described below.

That is, since the outer peripheral surface of the protrusion 8 of the contact body 9 is cylindrical, in order to rotate the contact body 9, the protrusion 8 must be aligned with respect to the axis of the guide 6, as described above. When at right angles, the outer peripheral surface of the overhang 8'' and the inner surface 6a of the guide 6'
A predetermined gap (hereinafter referred to as "set gap") had to be provided between them.

If the setting gap is large, there is a drawback that the measurement accuracy decreases. This is because if the gap between the outer circumferential surface of the overhanging portion 8 of the contact body 9 and the inner surface 6a of the guide 6 is large, the end surface of the overhanging portion S of the contact body 9 will be attached to the inner end surface 6b of the guide 6. It becomes possible to make a large movement in the direction orthogonal to the axis of the guide 6 while remaining in contact with the entire guide. In other words, since the degree of freedom of movement of the contact body 9 increases, the movement of the contact body 9 when the object to be measured comes into contact with it is not constant, and the position of the object to be measured when the switch emits a signal differs each time a measurement is made. This results in poor repeatability.

Further, if the set gap is made small enough to allow the contact body 9 to rotate by a predetermined amount, the decrease in measurement accuracy can be suppressed, but the projecting portion 8 of the contact body 9 may bite into the inner surface 6a of the guide 6. The drawback was that it was prone to malfunction. This is because the outer peripheral surface of the overhanging portion 8 of the contact body 9 is cylindrical.
When the overhang 8 is tilted with respect to the direction perpendicular to the axis of the guide 6,
The outer shape of the overhanging portion 8 when viewed from the axial direction of the guide 6 is elliptical, and the overhanging portion 8 contacts the inner surface 6a of the guide 6 at approximately a point at the major diameter end of the ellipse. For example, if the object to be measured comes into contact with the object from the direction indicated by the arrow in FIG. do. In other words, the contact body 9 is supported only at this one place, excluding the sphere I2, against the force that tries to push the contact body 9 downward, and the surface pressure there becomes high. For this reason, the protruding portion 8 of the contact body 9 bites into the inner surface 6a of the guide 6 at this location, and even if the object to be measured leaves the contact 7, the contact body 9 does not return to its original position. , it is easy to malfunction.

The present invention has been made in view of the above-mentioned conventional problems, and it is an object of the present invention to provide a contact detection device that has high repeatability and is less likely to cause malfunctions due to sticking or the like in the sliding portion.

"Means for Solving the Problems" A contact detection device of the present invention includes a housing provided with a guide having an inner surface having a circular cross section and an inner end perpendicular to the inner surface;
A rod-shaped contact is provided with a disc-shaped protruding part extending perpendicularly to the axis of the contact, the protruding part is disposed within the guide, and one end of the contact is A contact body is arranged to protrude to the outside of the housing, and a contact body is disposed on the other end side of the contact so as to be movable in the axial direction of the guide, and the guide is moved in response to rotational displacement of the contact body. a movable body that moves in the axial direction; a biasing member that presses the end of the projecting portion of the contact body against the inner end of the guide by pushing the movable body in the direction of the contact; and a switch that detects movement and issues a signal, and when the object to be measured contacts the contact of the contact body, the switch detects linear movement of the moving body due to displacement of the contact body. A contact detection device configured to detect contact between an object to be measured and a contact body, characterized in that the outer circumferential surface of the protrusion of the contact body is a spherical surface facing the inner surface of the guide with a slight gap.・"Function" In the contact detection device of the present invention, when the object to be measured comes into contact with the contactor, the contact body is configured such that when the object to be measured comes into contact with the contactor, the end surface of the overhanging portion of the contact body is exposed to the other side, leaving only the side in contact with the object to be measured. The part pivots away from the inner end of the guide. In response, the movable body moves in the opposite direction to the contact body. This movement of the movable body causes the switch to emit a signal.

The outer circumferential surface of the protrusion provided on the contact body is a spherical surface that faces the inner surface of the guide with a small gap, so that it comes into line contact with the inner surface of the guide when the contact body rotates. Therefore, the surface pressure at the portion where the outer circumferential surface of the protruding portion provided on the contact body contacts the inner surface of the guide is smaller than that in the conventional case, and it is difficult for jamming to occur at this portion.

Furthermore, since the gap between the outer peripheral surface of the overhang and the inner surface of the guide is minute, the degree of freedom of movement of the contact body is small, and the movement of the contact body is constant, so repeatability is high.

``Example'' An example of the present invention will be described below with reference to FIGS. 1 to 3.

In FIG. 1, 14 is a housing. A guide 15 is fixed inside this housing 14. The guide 15 has an inner surface 15a having a circular cross section, an inner end surface 15b perpendicular to the inner surface 15a, and an opening 15c provided in a wall forming the inner end 15b. Fixed. A contact body 17 is disposed on the central axis of the opening 15c of the guide 15. The contact body 17 is a contact 18 that is entirely rod-shaped and has a spherical portion 18a at one end.
An air guide 19 (the details of which will be described later) is screwed onto the locator 2I, which is fixed with a screw 20, and has a disc-shaped projection 21a extending perpendicularly to the axis of the contact 18. It is attached and fixed with screws 22. In this contact body 17, the projecting portion 21a is the guide I5.
Inside, the spherical portion 18a side of the contact 18 is arranged so as to protrude to the outside from the opening 15c of the guide 15.

Here, the outer periphery of the projecting portion 21a of the locator 21 has a center X on the central axis of the contactor 18, and is a spherical surface whose diameter d is slightly smaller than the inner diameter of the guide I5.

Therefore, the outer periphery of the overhanging portion 21a, surface B, is a guide! They face the inner surface 15a of 5 over the entire circumference with a small gap. Moreover, in this state, the overhanging portion 21a is
It does not change even if it is tilted in a direction perpendicular to the axis of 5. Further, an annular projection 21b is provided in an annular shape around the axis of the contact I8 at the end of the projecting portion 21a of the locator 21 on the inner end surface 15b side of the guide 15.

Further, at the end of the locator 21 opposite to the spherical part 18a of the contact 18, a ball receiving part 21d having a conical end surface 21c whose center axis is the axis of the contact 18 is formed.

Further, in the housing 14, a rod (
A moving body) 23 is provided. The rod 23 consists of a prismatic rod main body 23a and a ball receiving part 23c provided at one end thereof and having a conical end surface 23b. The rod 23 is attached movably in the axial direction by a roller guide 24, as shown in FIG. There is. And the ball receiving part 2 of this rod 23
A sphere 24 is located between 3c and the ball receiving portion 21d of the locator 21.
A is interposed.

Also, the housing! 4, a support plate 25 is fixed with a bolt 26 so that the rod 23 passes through it.

Then, the locator 2 of the rod body portion 23a of the rod 23
A movable plate 27 is fixed to the end opposite to 1.

A tension spring 3.0 is attached between the support plate 25 and the movable plate 27 by being hooked between a hook 28 attached to the support plate 25 and a screw hook 29 screwed onto the movable plate 27. There is. This spring 30 urges the rod 23 in the direction of the locator 21 and also urges the locator 21 to the left in FIG. 1 via the sphere 24a. The end surface of 21b is pressed against the inner end surface 15b of the guide 15.

Here, the screw hook 29 is fixed by a nut 31 after adjusting the amount of extension of the tension spring 30 according to the screwing amount.

Further, a switch holder 32 is fixed to the support plate 25. A switch 33 is screwed onto the switch holder 32 so that its contact 33a faces toward the movable plate 27, and is fixed with a nut 34. A switch drive screw 35 is screwed onto the movable plate 27 at a position facing the contact 33a of the switch 33. This switch drive screw 35 is connected to the overhanging portion 21.
The annular projection 21b formed on the inner end surface 15b of the guide 15 is pressed against the inner end surface 15b of the guide 15.
After adjusting the screwing amount so that the tip of the rod 23 comes into contact with the contact 33a of the switch 33 when the rod 23 is positioned in an annular contact with the nut 36
Fixed by

Furthermore, a non-contact position detector 37 is provided within the housing 14 . The non-contact position detector 37 is provided to control the moving speed of the object to be measured in order to shorten measurement time. This is provided to control the speed to a low speed when approaching.

This non-contact position detector 37 utilizes light reflection using a light emitting element and a light receiving element. As shown in FIG. 3, four non-contact position detectors 37 are arranged in a ring shape around the periphery of the housing 14.

Further, a glass plate 38 is disposed in the housing 14 so as to cover the receiving and emitting parts of the non-contact position detector 37, respectively.
Four are installed.

Further, this device is provided with a fluid flow path for introducing air or air containing oil or the like from the outside and distributing it to appropriate locations. This flow path is provided in order to timely blow air or air containing oil onto the contactor 18 or the glass plate 38 to remove foreign substances such as chips and cutting oil attached thereto. .

First, an air inlet 39 is formed on the outer surface of the housing I4. A hole 40 is formed in the housing 14 so as to be continuous with the air introduction port 39. Also,
A plain air guide 41 is screwed into the housing 14 at the end of the hole 40 . Plain air guide 4
1 has a circulation hole 42 inside and a disc-shaped overhang 41 at the end.
a is formed, and the outer circumferential surface continuous to this overhang portion 41a is shaped like a cone. This plain air guide 41 is arranged so that its circulation hole 42 is continuous with the hole 40. Further, the housing 14 is formed with a conical surface that faces the conical outer circumferential surface formed on the brain air guide 41 with a slight gap, and the conical surface and the conical surface formed on the plain air guide 41 are opposite to each other with a slight gap. A constricted portion 43 is formed by the outer peripheral surface. Further, an arc air guide 44 is interposed between the projecting portion 41a of the plain air guide 41 and the housing 14. Here, as shown in FIG. 3, four plane air guides 41 and four arc air guides 44 are provided at positions adjacent to the glass plate 38, respectively.

A radial air guide 45 is provided at a portion where the guide 15 is fixed to the housing 14 with a bolt 16 so as to be interposed between the guide 15 and the housing I4. A hole 46 is formed in the housing 14 at a position that is continuous with the hole 40 and the radial air guide 45 and connects them. The portion I surrounding the locator 21 inside the radial air guide 45 is the bellows 4.
7 is provided. The bellows 47 is made of a material such as rubber and has flexibility. This bellows 47 is a flow path 17a provided in the contact body 17.
The locator 2I is attached between the locator 2I and the radial air guide 45 so as to connect the locator 2I and the inside of the radial air guide 45.

The air guide 19 screwed onto the contactor 18 has a circular protrusion 19a at its end, and the inner circumferential surface continuous with the protrusion 19a is conical. A conical surface is formed on the outer periphery of the contactor 18, and the conical inner peripheral surface continuous with the protrusion 19a of the air guide 19 faces the conical surface with a slight gap. A constricted portion 48 is formed with the conical inner circumferential surface of No. 19.

Further, a rubber cover 49 is provided at a portion where the contact body 17 protrudes from the opening 15c of the guide 15 so as to cover the opening 15c. The rubber cover 49 prevents foreign matter such as chips and cutting oil from entering the main parts of the device inside the housing 14. This rubber cover 49 is fixed to the guide 15 with a cover presser 50 and bolts 51.

Next, the operation of the contact detection device having the above configuration will be explained.

When the object to be measured is not in contact with the contactor 18, the annular protrusion 21b on the end surface of the projecting portion 21a of the locator 21 contacts the inner end surface 15b of the guide 15 in an annular shape due to the bias of the spring 30. There is.

When the object to be measured approaches from a direction perpendicular to the axis of the contactor 18 and comes into contact with the spherical part 18a of the contactor 18, the locator 21 moves the annular protrusion 21 on the end surface of the overhanging part 21a.
At b, the guide 15 is rotated leaving only the side in contact with the object to be measured and leaving the other portions away from the inner end surface 15b of the guide 15. As a result, the rod 23 is moved to the right in FIG. 1 via the sphere 24a. This rod 2
3 moves the switch drive screw 35 away from the contact 33a of the switch 33, the switch 33 emits a signal, and contact with the contact 18 of the object to be measured is detected.

At this time, the projecting portion 21a of the locator 21 is inclined with respect to the direction perpendicular to the axis of the guide, but since the outer circumference of the projecting portion 21a is spherical as described above, the guide 15 of the projecting portion 21a The outer shape seen from the axial direction remains circular. Therefore, the contact body 17 is supported against the force of the object to be measured pushing the contact body 17 by the sphere 24a and the semicircle on the opposite side of the inner surface 15a of the guide 15 where the object to be measured comes into contact. becomes. In other words, the inner surface 15a of the guide 15 receives the projecting portion 21a in line contact. Therefore, in this device, the projecting portion 21a is less likely to bite into the inner surface 15a of the guide 15 at this location, and malfunctions are less likely to occur.

Furthermore, since the gap between the outer circumferential surface B of the projecting portion 21a and the inner surface 15a of the guide 15 is minute, the movement of the contact body 17 is approximately only rotational movement, and the movement of the contact body 17 is constant. Therefore, repeatability is high.

Further, the shapes of the components that determine the relationship between the displacement amount of the contact body 17 and the movement type of the rod 23 are all axially symmetrical with respect to the axis of the guide 15 when the object to be measured is not in contact with them.

Therefore, when the object to be measured approaches from a direction perpendicular to the axis of the contactor 18, the relationship between the amount of displacement of the contactor 17 and the amount of movement of the rod 23 is such that the object to be measured approaches the contactor 18. It remains constant even if the direction changes. Therefore, the above-mentioned working distance (distance traveled by the object to be measured before contact is detected) does not vary depending on the direction in which the object to be measured approaches the contactor 18.

On the other hand, in the above operation, from the air inlet 3°9,
Air etc. are pumped in at the appropriate time. This air etc. is divided into two systems: one that flows into the flow hole 42 of the plain air guide 41 through the hole 40, and one that branches from the hole 40 through the hole 46 and flows into the radial air guide 45. The former air flows out from the constriction part 43 and is directed toward the glass plate 38 by the projecting part 41a of the plain air guide 41 and the arc air guide 44. Also,
The latter air, etc. passes through the bellows 47 and reaches the contact body 17.
The air flows through the flow path 17a, flows out from the constriction part 48, is directed by the protrusion 19a of the air guide 19, and heads toward the spherical part 18a of the contactor 18. As a result, contact 1
Foreign matter such as chips and cutting oil adhering to the spherical portion 18a of 8 or the glass plate 38 is blown off and removed by air or the like as appropriate. Therefore, foreign matter may get caught between the contactor 18 and the object to be measured, resulting in poor measurement, or foreign matter adhering to the glass plate 38 may block the light receiving and emitting part of the non-contact position detector 37. The non-contact position detector 37 will not malfunction.

In this embodiment, the tip of the contactor 18 is made spherical, but when measuring the length of a cutting tool such as a drill, for example, since the tip is sharp, it is difficult to determine the position when making contact. Misalignment and slippage may cause measurement errors. In such a case, the tip of the contactor 18 may be shaped into a cube.

Furthermore, in the above description, the case where the contact detection device of this embodiment is fixedly attached to the body of a machine tool, etc., and the object to be measured is attached to the main shaft of the machine tool and moves is assumed. I am assuming that. However, in the contact detection device of this embodiment, the shank, etc. used for automatic tool change of a machine tool is fixed to the housing 14, and is thereby attached to the main shaft of the machine tool, etc., and is moved relative to a stationary object to be measured. May be used.

"Effects of the Invention" When the contact detection device of the present invention is activated, the inner surface of the guide receives the protruding part of the contact body in line contact. This has the effect that it is difficult to bite into the side surface at this location, and malfunctions are less likely to occur.

Furthermore, since the gap between the protrusion of the contact body and the inner surface of the guide is minute, the degree of freedom of movement of the contact body is small, and the movement of the contact body is constant, so repeatability is high.

[Brief explanation of the drawing]

1 to 3 are views showing embodiments of the present invention, in which FIG. 1 is a sectional view of the main part of the contact detection device, FIG. 2 is a sectional view taken along FIG. 3 is a view taken in the direction of the ■ arrow in FIG. FIGS. 4 to 8 illustrate a conventional contact detection device. FIG. 4 is a diagram showing the first conventional contact detection device;
FIG. 5 is a view taken in the direction of the ■ arrow in FIG. 4, FIG. 6 is an electric circuit diagram of the first conventional contact detection device, and FIG. 7 is a diagram showing the characteristics of the first conventional contact detection device. Moreover, FIG. 8 is a diagram showing a second conventional contact detection device. 17...Contact body, 18...Contact element, 2
1a...Protruding portion, 23...Moving body (rod), 30...Biasing member (tension spring), 33
······switch.

Claims (1)

[Claims] A housing provided with a guide having an inner surface with a circular cross section and an inner end surface perpendicular to the inner surface, and a disc-shaped overhang extending from the rod-shaped contact perpendicularly to the axis of the contact. a contact body in which the projecting portion is disposed within the guide and one end of the contact protrudes to the outside of the housing; a moving body that is arranged to be movable in the axial direction of the guide and moves in the axial direction of the guide in response to rotational displacement of the contact body; The device includes an urging member that presses the end surface of the projecting portion against the inner end surface of the guide, and a switch that detects movement of the moving body and issues a signal, and the object to be measured comes into contact with the contact of the contact body. In the contact detection device, the linear movement of the movable body accompanying the displacement of the contact body is detected by the switch to detect contact between the object to be measured and the contact body. A contact detection device characterized in that an outer peripheral surface is a spherical surface that faces the inner surface of the guide with a small gap.