JPS60104202A - Displacement quantity detecting device - Google Patents

Abstract

PURPOSE:To prevent generation of a measuring error, and to raise an accuracy by providing a coil and a magnet so as to be opposed to each other among a basic part, the first movable member and the second movable member, so that a direction and a current value of a current flowing to the oil can be controlled. CONSTITUTION:The first coil 13 and the first magnet 14 of E-type are provided between an arm 31 of the first movable part 4 and the second movable part 8. Each wire of the first coil 13 is combined so as to cut a magnetic flux of the magnet 14, when the first movable part 4 is displaced in the X direction. Also, the second coil 15 and the second magnet 16 are provided between the second movable part 8 and an arm 30 of a basic part 1. In such a structure, when a current is supplied to the coils 13, 15, a power is generated between the magnet and the coil, and magnitude of its power is proportional to magnitude of the flowing current. In this way, by controlling a current value, no measuring error is generated, and the measuring accuracy can be raised.

Description

Detailed Description of the Invention This invention generates a measuring force in any axis and direction required by a three-dimensional displacement detection device (probe) used in a three-dimensional coordinate measuring machine, etc., and further uses the same mechanism to generate a measuring force in a specified direction. This relates to a mechanism that clamps the movement of an axis to a mechanical origin.

The three-dimensional displacement detection device has detection directions in all directions in three-dimensional space, so when the contact is free, that is, not in contact, it is at the mechanical origin (center) and cannot be detected in any direction. It also does not have the ability to measure. When a displacement is applied in one direction due to contact, a force is generated in the opposite direction of this displacement, that is, toward the center, and this acts as a measuring force. If the worker constantly contacts the object to be measured by manual measurement, no problem will occur, but if the measurement is performed automatically using the NG sub-control, a similar problem will occur.

Therefore, when automatically measuring the object W to be measured as shown in Fig. 1,
The three-dimensional displacement detection type contact attached to the three-dimensional coordinate measuring machine is subjected to NG sub-control so as to draw a locus (dotted line) of one value of the installed dew. In the case of states A to B in FIG. 1, the contactor contacts the object to be measured and causes a displacement in the three-dimensional displacement detection type, and it is detected that there is an error. However, in the conditions shown in FIG. 1 B to C, the contact only passes through the space showing the J method of the dew installation and does not come into contact with the object to be measured. At this time, the three-dimensional displacement detector maintains the mechanical origin and indicates that the N method error of the object to be measured is zero. To prevent such errors, judge the positional relationship between the three-dimensional displacement detector and the object to be measured, apply measuring force to the contact, and displace the tip of the contact only to cover the expected error range. Bye. The key point of the present invention is a method of applying measuring force in any direction without changing the origin position.

FIG. 2 shows an outline of the three-dimensional displacement detector on which the present invention is based. The displacement detection units for each of the x, y, and z axes basically have the same mechanism, and the displacement applied to the contact at the tip of the measuring section is sequentially transmitted to each unit via the filler, and the displacement is transmitted to each unit sequentially to detect x, y, respectively.

It is configured to detect only a displacement component in one axis direction of the Z orthogonal coordinate system. Since the mechanism of each unit is the same, I will explain about the X axis.

FIG. 3 shows the internal structure of the X-axis. The first movable member 4 is suspended by a pair of parallel springs 2.3 based on the foundation part 1,
A measuring shaft 12 is installed at the tip of 3, and then the contact 9 is connected through a filler.
is connected. Another set of parallel springs 6.7 is mounted parallel to the parallel springs 2.3 on the basis of the foundation part 1, and a second set of parallel springs 6.7
The driving section 8 is suspended. The parallel springs 2.3 and 6.7 have strong rigidity in the torsional direction and are designed to prevent displacement in directions other than the X direction. A mechanical stopper 10 is provided between the arm 30 extending from the base part 1 and the second movable part 8, and a 1Mfi stopper 5 is provided between the arm 31 extending from the first movable part 4 and the second movable part 8. , and springs 32 and 33 are provided to always bias the stopper into contact. Due to this Ill structure, the position of the contactor 9 of the measuring section is always at a fixed position during non-contact, and a stable mechanical origin can be obtained. Arm 30 of the base part 1 and arm 31 of the first movable part 4
A linear displacement detector 11 for detecting relative displacement is provided between the two, and is set so that the output signal is zero when at the mechanical origin.

In such a structure, when the contactor 9 is displaced to the right, the first movable portion 4 is displaced to the right against the force of the spring 32, and conversely, when the contactor 9 is displaced to the left, the first movable portion 4 is displaced to the right. 4 pushes the stopper 5 to the left, stretches the spring 33, and displaces the second movable part 8 to the left. The amount of displacement is output by linear detection N11. When the contactor 9 separates from the object to be measured and the displacement input disappears, it returns to the mechanical origin again by the force of the spring 32 or 33, and the output of the linear detector 11 also becomes zero.

Next, the measuring force generating mechanism, which is the first object of the present invention, will be explained. In FIG. 3, the arm 31 of the first movable part 4 and the second
A first coil 13 and an E-type first magnet 1 are placed between the movable part 8 and the movable part 8.
4 will be provided. Each wire of the first coil 13 is
When displaced in the direction, the magnetic flux of the magnet 14 is cut.

The structure itself is similar to the voice coil part of an acoustic speaker. Similarly, the second movable part 8 and the arm 30 of the base part 1
A second coil 15 and a second magnet 16 are provided between the two.

In the structure shown in B, a device (not shown) for supplying current to the coils 13 and 15 is provided to set the direction and magnitude of the current. When a positive current is supplied to the coils 13 and 15, a force is generated between the magnet and the coil, the direction of which is determined by the polarity of the magnet and the direction of the current, and becomes a repulsive force or an attractive force. The magnitude of the force is proportional to the magnitude of the flowing current. Now, a current is applied to the first coil 13 in a direction to generate a repulsive force.

As the current value increases, the repulsive force increases, and when it becomes greater than the force of the spring 32 that urges the stopper 5 into contact, the first movable part 4 moves to the right, and the filler and contactor that are connected to it move to the right. 9 also moves to the right. When the spring 32 stretches and reaches equilibrium with the repulsive force of the coil 13, the first
The movable part 4 stops. The repulsive force of the coil 13 at this time acts as a measuring force in the right direction. Note that when the first movable part 4 moves to the right, a reaction force acts on the second movable part 8 without moving it to the left, but the second movable part 8 is biased rightward by the spring 33, so it does not move. .

When generating a measuring force in the left direction, a current is applied to the second coil 15 in a direction that generates a repulsive force to displace the second movable portion to the left. A first movable part 4 and a filler connected thereto,
Since the contactor 9 is coupled with the spring 32 via the stopper 5, it is displaced to the left. Note that if the magnet and coil are mounted on the right side, the same operation will occur if an attractive force is generated and used as the measuring force. As explained above, it is possible to displace the position of the contact by applying a measuring force in any direction, so it is used by obtaining a signal in the moving direction of the contact from the NC control signal and displacing the contact in the moving direction. I can do it.

The structure of the tank for this device is shown in Figure 3. In addition, if there is a concern that the weight of the movable part will increase due to the enlargement of the magnet and worsen the movement of the measuring part, as shown in Figure 4, the first magnet 14, the second magnet 14, Even if the magnet 16 is attached to the arm portion 30 from the base portion 1, the operation and efficiency are the same.

Next, a clamp mechanism using the same mechanism, which is the second object of the present invention, will be explained. In FIG. 5, a case is illustrated in which the three-dimensional displacement detection device is moved along the X axis in the (-) direction (to the left in the figure) and brought into contact with the object to be measured placed on the XY plane. After the contact 9 contacts the object to be measured W at point ■ at the point where the origin of the three-dimensional displacement detection device is Xo, further -a
When moving in the JiX axis direction, the movable part within the three-dimensional displacement detection device causes displacement. If there is no displacement in the Y-axis direction, the amount of time-synchronized displacement of B will be Δ1 in the opposite direction to -a, but in general, it is determined by the contact angle between the object to be measured and the contact, the coefficient of friction, and the mutual relationship between each axis. X-axis direction displacement O1Y due to non-uniformity of measurement force, etc.
Only the shaft displacement causes arbitrary displacement until it shows Δ4 and is not constant. It becomes even more complicated when Z-axis displacement is included. In actual measurement, it is necessary to detect a specific specified axial displacement, and for this purpose a clamping device is required to prevent any other axial displacement from occurring. In the present invention, it is possible to restrict the movement of the movable part by using the above-mentioned measuring force generating magnet and coil without particularly providing a clamping device, and by passing current through the coil in the direction in which the attractive force is generated.

As described in detail below, the present invention is a three-dimensional displacement detection device.
Two magnets and electromagnetic coils are provided in each YZ axis unit, and by selectively attracting or repelling the two electromagnetic coils of the desired axis and controlling the current value, it is possible to measure force by displacing that axis. As well as generating
The same mechanism is used to clamp the desired axis to the mechanical origin, making it possible to perform highly accurate measurements without causing measurement errors, especially during automatic measurements.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the measurement position in the case of NC measurement without applying a measuring force, Fig. 2 is an external view of a three-dimensional displacement detector incorporating the present invention, and Fig. 3 is an embodiment of the present invention. FIG. 4 is a front view of another embodiment, and FIG. 5 is an explanatory diagram showing variations in measured values on the XY plane in a state where the shaft is not clamped. 1: Foundation part 2.3.6.7: Parallel spring 4: First movable part 5, lO: Stopper 8: Second movable part 9: Contactor ll: Linear detection type 13:
First coil 14: First magnet 15: Second coil 16:
Second magnet patent applicant Tokyo Seimitsu Co., Ltd.

Claims (1)

[Claims] (1) In a fixed-direction displacement detection device configured with first and second movable members related to each other by two sets of parallel springs and a measurement unit attached to the first movable member, the base part; A fill and a magnet are provided opposite the same one of the first movable member and the second movable member.
A displacement detection device that is capable of controlling an I current value, and is capable of generating a measuring force in any direction or clamping any axial displacement by controlling the direction and value of this current. (21qti Claim 1: A displacement detection device characterized in that a coordinate system of xyz axes in the displacement direction is constructed using three displacement detection devices in ζ.