JP2015055515A - Lifting device of measuring instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lifting device of a measuring instrument capable of balancing a weight, a drive, and a moment of a lifting member.SOLUTION: A weight of a lifting member 32 can be balanced by a counter weight mechanism part 36 composed of a pulley 38, a wire 40, and a counter-weight 42. One end of the wire 40 of the counter weight mechanism part 36 is connected to a first position A which is offset in a shaft direction of a screw rod 18 of a motor 20 with respect to a center of gravity G of the lifting member 32, and this connection allows a drive to be balanced. Since the first position A and a second position B are separated by "L" in a horizontal direction, the moment of the lifting member 32 can be balanced by generating a clock-wise moment of "F(N)×L" in the lifting member 32 by operating a tension application member 52.

Description

  The present invention relates to a lifting device for a measuring machine, and more particularly to a lifting device for a measuring machine that moves a detector up and down along a column that is erected on a main body of a roundness measuring machine.

  The roundness measuring machine includes a measurement table that is rotatably supported by a main body, and a detector that has a measuring element that comes into contact with a workpiece placed on the measurement table. The roundness measuring machine rotates the measurement table in a state where the measuring element is in contact with the workpiece, and measures the roundness and shape of the workpiece based on the displacement amount of the measuring element.

  The detector is attached to a carriage via an arm, and the carriage is supported by a column vertically provided on the main body so as to be movable up and down. The carriage is moved up and down by the power of a motor that rotates the screw rod, with the nut screwed into the screw rod of the ball screw device. The carriage is connected to the counterweight mechanism.

  The counterweight mechanism is composed of a wire, a pulley, and a counterweight. The load on the motor is reduced by the counterweight balancing the weight of the elevating member comprising the detector, the arm, and the carriage. That is, the wire is wound around the pulley installed above the column, one end of which is connected to the carriage, and the other end is connected to the counterweight.

  By the way, when the lifting position (connection position) of the carriage by the wire is offset from the position of the center of gravity of the lifting member, the moment M (M = WL: W is the load of the lifting member (N): L is lifting the lifting member. Since the distance from the position to the center of gravity position of the elevating member is generated, the elevating member is inclined with respect to the column, or the column is deformed, resulting in a problem that the measurement accuracy is deteriorated.

  In order to solve the above problem, the lifting device of Patent Document 1 balances the moment by making the lifting position of the carriage (upper / lower table) by the wire coincide with the position of the center of gravity of the lifting member.

JP-A-5-322507

  However, as in Patent Document 1, when the lifting position of the carriage by the wire is made coincident with the position of the center of gravity of the elevating member (when the moment is balanced), the lifting position is determined from the driving point of the motor (axial center of the screw rod). Are separated (because the driving balance is poor), the raising / lowering member is also inclined with respect to the column or the column is deformed, resulting in a problem that the measurement accuracy is deteriorated. Further, in order to balance the drive, the lifting position has to be brought close to the drive point, so that there is a problem that the moment balance is lost and a moment is generated in the elevating member.

  That is, it has been difficult for the conventional lifting device of the measuring machine to balance the weight balance of the lifting member, the balance of driving, and the moment of the lifting member.

  If the motor drive point and the lifting position are separated, the resistance force when operating the counterweight mechanism due to friction between the pulley and the wire constituting the counterweight mechanism, the resistance of the bearing that rotates the pulley, etc. Will occur. Due to this resistance force, a moment is generated when the driving point of the motor is separated from the lifting position, and as a result, the driving balance is deteriorated.

  This invention is made in view of such a situation, and it aims at providing the raising / lowering apparatus of the measuring machine which can balance the weight balance of an raising / lowering member, the balance of a drive, and the moment of an raising / lowering member. .

  In one aspect of the present invention, in order to achieve the above object, an elevating member that is movable up and down along a column erected on a main body of a measuring instrument, and a drive unit that drives the elevating member to move up and down along the column; A first pulley attached to an upper portion of the column; a first position wound around the first pulley and having one end offset in a drive axis direction of the drive unit with respect to a gravity center position of the elevating member A counterweight mechanism having a first wire coupled to the first wire and a counterweight coupled to the other end of the first wire; a second pulley attached to a lower portion of the column; and the second pulley Wrapped around a pulley, one end is connected to the counterweight, and the other end is a second position of the elevating member, and is connected to a second position sandwiching the first position with the center of gravity position. First Providing a wire, and a lifting device for measuring machine and having a a counter moment assembly with a tensioning member for applying tension to said second wire.

  According to the aspect of the present invention, the weight balance of the elevating member can be achieved by the counterweight mechanism portion including the first pulley, the first wire, and the counterweight. Also, one end of the first wire of the counterweight mechanism is connected to a first position that is offset in the direction of the drive axis of the drive unit with respect to the position of the center of gravity of the elevating member. it can. Furthermore, the other end of the second wire of the counter moment mechanism is connected to the second position of the lifting member and the second position sandwiching the first position with the center of gravity position. The moment can be balanced.

  That is, according to one aspect of the present invention, by connecting the lifting member and the counterweight via the second pulley and the second wire, the system that connects the lifting member and the counterweight is a closed loop, A tension applying member is provided at a connecting portion between the other end of the second wire and the elevating member, and tension is applied to the second wire by the tension applying member. This tension is set to a value that cancels out the moment generated in the elevating member in the state where the counter moment mechanism portion does not exist.

  Therefore, according to one aspect of the present invention, the counterweight mechanism can balance the weight of the lifting member and the drive, and the counter moment mechanism can balance the moment of the lifting member. . Thereby, since the pressurization applied to the elevating member in order to balance the moment can be reduced, the drive unit can be miniaturized and an inexpensive apparatus can be provided.

  In addition, since the displacement of the column due to the moment can be eliminated, highly accurate measurement can be performed.

  Further, since the first position (lifting position) is close to the drive shaft, the elevating member can be driven at a position close to the friction center of gravity. As a result, changes in the postures of the elevating member and the column are reduced, so that accurate driving is possible.

  The “friction center of gravity” here refers to the center line of the resistance force when the counterweight mechanism is operated.

  In addition, the conventional counterweight mechanism portion is less expensive than the additional moment balance mechanism, since there are fewer elements (counter moment mechanism portion) to be added.

  In one aspect of the present invention, it is preferable that the tension applying member is disposed at a connecting portion between the other end of the second wire and the elevating member.

  According to one aspect of the present invention, the tension applying member can be easily adjusted by arranging the tension applying member at the connecting portion between the other end of the second wire and the elevating member.

  In one aspect of the present invention, it is preferable that the tension applying member includes a spring member that connects the other end of the second wire and the elevating member, and an adjustment member that adjusts an urging force of the spring member.

  According to one aspect of the present invention, the tension applying member is constituted by the spring member and the adjusting member, and the biasing force of the spring member is adjusted by the adjusting member. For example, when the spring member is a compression coil spring, the tension applied to the second wire can be easily adjusted by adjusting the extension amount.

  According to the lifting device of the measuring machine of the present invention, it is possible to balance the weight balance of the lifting member, the balance of driving, and the moment of the lifting member.

Longitudinal section of detector lifting device of roundness measuring machine Plan view of the detector lifting device shown in FIG. The side view which expanded and showed the tension | tensile_strength provision part of the detector raising / lowering apparatus shown in FIG.

  Hereinafter, preferred embodiments of a lifting device for a measuring machine according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a longitudinal sectional view of a detector lifting / lowering device 10 of a roundness measuring machine to which a lifting / lowering device for a measuring machine according to the present invention is applied. FIG. 2 is a plan view of the detector lifting apparatus 10 shown in FIG. FIG. 3 is an enlarged side view showing the tension applying member 52 of the detector lifting device 10.

  A detector lifting device 10 shown in FIG. 1 includes a column 12, and the column 12 is erected in a vertical direction on a main body 14 of a roundness measuring machine.

  The column 12 is provided with a ball screw device (drive unit) 16, and a screw rod 18 of the ball screw device 16 is disposed along the column 12 in the vertical direction. The upper and lower ends of the screw rod 18 are rotatably attached to the column 12 via a bearing (not shown), and are rotated around the shaft center by the power of the motor 20 of the ball screw device 16. This motor 20 is also attached to the column 12.

  A nut 22 of the ball screw device 16 is screwed onto the screw rod 18. The nut 22 is fixed to the carriage 24. A detector 30 is attached to the carriage 24 via a rod-shaped arm 26 and an L-shaped bracket 28 as shown in FIG. That is, the carriage 24, the arm 26, the bracket 28, and the detector 30 constitute a lifting member 32 that can be lifted and lowered along the column 12. The elevating member 32 is moved up and down along the screw rod 18 by driving the motor 20 in the forward direction and the reverse direction. The carriage 24 has a cylindrical shape, the column 12 is disposed therein, and a plurality of slides for guiding the raising / lowering operation of the carriage 24 are provided between the inner wall surface of the carriage 24 and the outer wall surface of the column 12. A member 34 is arranged.

[Counterweight mechanism]
The counterweight mechanism 36 includes a pair of pulleys (first pulleys) 38, a wire (first wire) 40, and a counterweight 42 as shown in FIGS.

  The pulley 38 is attached to a top plate 44 fixed to the upper part of the column 12. The wire 40 is wound around the pulley 38, and one end of the wire 40 is offset in the direction of the screw rod 18 (drive shaft) of the motor (drive unit) 20 with respect to the gravity center position G of the elevating member 32. Connected to A. The first position A is provided on a bracket 25 projecting from the inner wall surface of the carriage 24 so as to approach the axis of the screw rod 18. The column 12 is provided with a clearance groove 13 in the vertical direction for allowing the bracket 25 to escape. On the other hand, the other end of the wire 40 is connected to the center of gravity of the upper surface of the counterweight 42.

[Counter moment mechanism]
The counter moment mechanism 46 includes a pulley (second pulley) 48, a wire (second wire) 50, and a tension applying member 52.

  The pulley 48 is attached to a bottom plate 54 fixed to the lower portion of the column 12. The wire 50 is wound around the pulley 48 and one end thereof is connected to the position of the center of gravity of the bottom surface of the counterweight 42. The other end of the wire 50 is connected to a second position B of the elevating member 32 and a second position B sandwiching the first position A with the center of gravity position G of the elevating member 32. Further, as shown in FIG. 2, the second position B is set on an extension line of a line segment connecting the gravity center position G and the first position A.

  The center-of-gravity position G moves by sliding the arm 26 in the horizontal direction with respect to the carriage 24. In order to balance the moment described below well, the second position B and the first position are used. It is preferable that the center-of-gravity position G is fixed on the extension line of the line connecting A. Therefore, in this case, a counterweight (not shown) is moved along the arm 26 in the direction opposite to the sliding direction of the arm 26 in conjunction with the operation of sliding the arm 26 with respect to the carriage 24 in the horizontal direction. Thus, it is preferable to provide a weight balance mechanism that fixes the center of gravity position G to the position shown in FIG. However, even if the weight balance mechanism is not provided, the moment balance in the front-rear direction can be obtained as viewed from the front of the apparatus, and therefore the weight balance mechanism is not essential.

  On the other hand, a tension applying member 52 that applies tension to the wire 50 is disposed at a connecting portion between the other end of the wire 50 and the elevating member 32.

  As shown in FIG. 3, the tension applying member 52 includes a compression coil spring (spring member) 56, an adjustment member including a washer 58 and a pair of nuts 60.

  The other end of the wire 50 is connected to the lower end of the pin 62, and the pin 62 is inserted into the hole 65 of the bracket 64 fixed to the carriage 24. The lower end of the compression coil spring 56 is placed on the bracket 64, and the pin 62 is inserted through the inside thereof. A screw rod 66 is provided at the upper end of the pin 62, and a washer 58 is inserted into the screw rod 66, and a nut 60 is screwed onto the screw rod 66 from above the washer 58.

  Therefore, by adjusting the position of the washer 58 by the nut 60 and adjusting the extension amount of the compression coil spring 56, the tension in the direction of arrow C can be applied to the wire 50, and the lifting member 32 has the arrow D as the reaction force. A directional load F (N) can be applied.

[Features of Detector Lifting Device 10]
First, the weight balance of the elevating member 32 can be achieved by the counterweight mechanism portion 36 including the pulley 38, the wire 40, and the counterweight 42. Further, one end of the wire 40 of the counterweight mechanism 36 is connected to the first position A that is offset in the axial direction of the screw rod 18 of the motor 20 with respect to the center of gravity position G of the elevating member 32, so that driving is performed. Can balance.

On the other hand, when the counter moment mechanism portion 46 is not provided and only the counterweight mechanism portion 36 is configured, the lift member 32 has a counterclockwise moment M (M = WL ₁ : W is the lift member) as shown in FIG. 32 (N): L ₁ is a distance from the first position A (lifting position) to the center of gravity position G of the elevating member 32), so that the elevating member 32 is inclined with respect to the column 12, There is a problem that 12 is deformed and the measurement accuracy is deteriorated.

  Therefore, in order to solve the above problem, the counter moment mechanism unit 46 is provided in the detector lifting device 10 of the embodiment.

  That is, as shown in FIG. 1, the counterweight 42 is connected to the carriage 24 via the wire 50 at the second position B. The wire 50 is wound around the pulley 48. A tension applying member 52 is attached to the other end of the wire 50.

Since the first position A and the second position B are separated from each other by “L ₂ ” in the horizontal direction as shown in FIG. 3, the tension applying member 52 is operated and “F (N) × L ₂ ” in the clockwise direction. This moment is generated in the elevating member 32.

That is, the tension of the wire 50 is set by operating the tension applying member 52 such that “WL ₁ ” = “FL ₂ ”. Thereby, the moment applied to the elevating member 32 can be balanced. That is, the other end of the wire 50 of the counter moment mechanism 46 is the second position B of the elevating member 32 and sandwiches the first position A with the center of gravity position G, preferably the center of gravity position G and the first Since it is connected to the second position B set on the extension line of the line connecting the position A, the moment of the elevating member 32 can be balanced.

  Therefore, according to the detector lifting device 10 of the embodiment, the weight balance and driving balance of the lifting member 32 can be balanced by the counterweight mechanism 36, and the moment of the lifting member 32 by the counter moment mechanism 46. Can balance.

  Thereby, since the pressurization given to the raising / lowering member 32 in order to balance a moment can be reduced, a drive part can be reduced in size and an inexpensive apparatus can be provided.

  In addition, since the displacement of the column 12 due to the moment can be eliminated, highly accurate measurement can be performed.

  Further, since the first position A is close to the axis of the screw rod 18, the elevating member 32 can be driven at a position near the friction center of gravity. Thereby, since the attitude | position change of the raising / lowering member 32 and the column 12 reduces, an accurate drive is attained.

  In addition, the conventional counterweight mechanism part is less expensive than the separately added moment balance mechanism, since there are fewer elements (counter moment mechanism part 46) to be added. Note that the tension of the wire 50 is self-completed by a closed loop, and thus does not affect the balance relationship of the counterweight 42.

  On the other hand, according to the detector lifting device 10 of the embodiment, since the tension applying member 52 is disposed at the connecting portion (second position B) between the other end of the wire 50 and the lifting member 32, the tension applying member. The tension adjustment of the wire 50 by 52 can be easily performed.

  That is, the tension applying member 52 may be disposed at the connecting portion between the one end of the wire 50 and the counterweight 42, but the counterweight 42 is only suspended by the wire 40 and is not fixed. Adjustment work becomes difficult.

  On the other hand, the elevating member 32 has the nut 22 screwed onto the screw rod 18 and is fixed to the screw rod 18 in a stationary state, so that the tension adjustment by the tension applying member 52 can be easily performed.

  Further, according to the detector lifting device 10 of the embodiment, the tension applying member 52 is configured by the compression coil spring 56 and the adjusting member including the washer 58 and the nut 60, and the biasing force of the compression coil spring 56 is adjusted by the adjusting member. doing. Thereby, the tension | tensile_strength provided to the wire 50 can be adjusted easily.

  In the embodiment, the roundness measuring device is exemplified as the measuring device, but the measuring device is not limited to this, and the lifting device of the present invention can be applied to any measuring device provided with a lifting member.

  DESCRIPTION OF SYMBOLS 10 ... Detector raising / lowering device, 12 ... Column, 13 ... Groove, 14 ... Main body, 16 ... Ball screw device, 18 ... Screw rod, 20 ... Motor, 22 ... Nut, 24 ... Carriage, 25 ... Bracket, 26 ... Arm, DESCRIPTION OF SYMBOLS 28 ... Bracket, 30 ... Detector, 32 ... Elevating member, 34 ... Sliding member, 36 ... Counterweight mechanism part, 38 ... Pulley, 40 ... Wire, 42 ... Counterweight, 44 ... Top plate, 46 ... Counter moment mechanism , 48 ... pulley, 50 ... wire, 52 ... tension applying member, 54 ... bottom plate, 56 ... compression coil spring, 58 ... washer, 60 ... nut, 62 ... pin, 64 ... bracket, 65 ... hole, 66 ... screw rod

Claims (3)

An elevating member that is movable up and down along a column erected on the main body of the measuring machine;
A drive unit that drives the lifting member up and down along the column;
A first pulley attached to an upper portion of the column; a first pulley wound around the first pulley and having one end offset in a drive axis direction of the drive unit with respect to a gravity center position of the elevating member A counterweight mechanism having a first wire to be coupled and a counterweight coupled to the other end of the first wire;
A second pulley attached to a lower portion of the column, wound around the second pulley, one end connected to the counterweight, and the other end being a second position of the elevating member, and the center of gravity A counter wire mechanism connected to a second position that sandwiches the first position at a position, and a counter moment mechanism section including a tension applying member that applies tension to the second wire;
A lifting device for a measuring machine characterized by comprising:   The lifting device for a measuring machine according to claim 1, wherein the tension applying member is disposed at a connecting portion between the other end of the second wire and the lifting member.   The measuring machine according to claim 1, wherein the tension applying member includes a spring member that connects the other end of the second wire and the elevating member, and an adjustment member that adjusts an urging force of the spring member. lift device.

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