JPH0146264B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a chuck slip detection device for a shaft component processing system that performs drilling or the like on a shaft component such as a crankshaft.

(Prior Art) Recently, machining of shaft parts such as crankshafts is often carried out on medium-sized and medium-weight production lines. Note that this medium-sized, medium-weight line is a processing line that is solely responsible for processing workpieces of various sizes.

By the way, on this medium-sized and medium-weight production line, drilling holes such as oil holes in the journal pin of the crankshaft is performed by automated machine tools such as robots and NC-only machines, so the crankshaft must be clamped. The machining is performed while being held in a fixed position relative to the machine tool by a jig to ensure machining accuracy.

This clamping jig includes a holding member that holds the crankshaft from both ends to fix the position of the crankshaft in the axial direction, and a holding member that holds at least one end of the crankshaft and clamps each part of the crankshaft in the rotational direction. A structure having a chuck for fixing the position of the is used.

(Problem to be Solved by the Invention) However, since the gripping force of the crankshaft by the chuck is required to cause as little damage as possible to the crankshaft, the gripping force must be weakened accordingly. Thrust force, etc. may cause relative slippage between the chuck and crankshaft at the gripping part (chuck slip), and in this case, the rotational position of each part of the crankshaft may shift and the machining accuracy deteriorates. There is a problem in that the waste flows into subsequent processes, causing damage to machine tools in subsequent processes.

The present invention has been made in view of the above circumstances, and its purpose is to provide a chuck slip detection device for a shaft component machining system that prevents defective products from flowing into subsequent processes. .

(Means for solving problems) Therefore, the present invention has the following configuration.

That is, in a shaft component machining system equipped with a clamp jig that grips a part of a shaft component, which is a workpiece, with a chuck during machining and fixes the rotational direction position of each part of the shaft component, It is possible to come into contact with
an arm mechanism including at least a pair of rotating arms that sandwich the eccentric portion when they come into contact; an arm drive mechanism that rotates the pair of arms in synchronization; and at least one of the plurality of rotating arms. a rotation angle detector that detects one rotation angle; and a rotation angle detector that controls the arm drive mechanism to bring the plurality of arms into contact with the eccentric portion before and after processing the shaft component, and controls each of the contact points. A chuck slip detection device for a shaft component machining system, comprising: means for acquiring data from the rotation angle detector at each time of contact; and comparison means for comparing data at each time of contact.

(Operation of the Invention) In this configuration, first, the eccentric portion of the shaft component moves around the axis of the shaft component by rotation of the shaft component. The rotation angle of the rotation arm changes depending on the position of the eccentric portion. Therefore, if no chuck slip occurs,
Since there is no change in the position of the eccentric part, there is no change in the data from the rotation angle detector.On the other hand, if chuck slip has occurred, there is a change in the position of the eccentric part, so the data from the rotation angle detector does not change. Since there will be changes in the data, chuck slip can be detected by comparing the data before and after machining.

In addition, since the eccentric part of the shaft component is sandwiched between a pair of rotation arms that rotate in synchronization before processing, the shaft component can be rotated by the power from the rotation arms. Therefore, it can be used to position each part of shaft parts in the rotational direction, and the center position between the pair of rotating arms remains constant regardless of the rotation angle, so it can be used for shaft parts of various sizes. This means that we can respond accordingly.

(Embodiment) An embodiment in which the present invention is applied to a system for drilling oil holes in a crankshaft will be described below with reference to the drawings.

In Figures 1 and 2, 1 is a base;
On this base 1, pedestals 2 and 3, an operating mechanism 4, pressing pins 5 and 5 and a chuck 6 constituting a clamp jig are installed.

A work W can be placed on the pedestals 2 and 3, and the pedestal 2 is placed and fixed on a stepped portion 8 of an upright wall 7 erected on the base 1. The stand 3 stands on the base 1 in the form of a column.

The actuation mechanism 4 consists of a fixed part 9 and a movable part 10. The fixed part 9 is fixed on a mounting base 11 that is protruded on the base 1, and the movable part 10 is attached to the fixed part 9. While reciprocating in the axial direction,
Rotates forward and backward around the axis. Moreover, this operating mechanism 4 has a built-in position indexing mechanism, and the movable part 1
The movement stroke in the axial direction and the rotation angle in the direction around the axis can be controlled to a predetermined amount. The movable part 10 is arranged to face the standing wall 7 at a distance, and the pedestals 2 and 3 are spaced apart from the standing wall 7.
and the opposing surface 13 of the movable part 10.

The pressing pins 5, 5 are pressed against each end of the workpiece W and serve to fix the position of the workpiece W in the axial direction, and one pressing pin 5 is fixed to the facing surface 12 of the upright wall 7 and is The other pressing pin 5 is fixed to the facing surface 13 of the movable part 10 and is opposed to the other end of the workpiece W on the pedestals 2 and 3. The pressing pins 5, 5 are made to face each other, and are pressed against each end of the workpiece W by activating the actuating mechanism 4 and moving the movable part 10 toward the upright wall 7. .

The chuck 6 is attached to the opposing surface 13 of the movable part 10, and grips the other end of the workpiece W to move the workpiece W.
The rotational direction position of each part is fixed. Reference numeral 14 denotes the main body of this chuck 6, and the chuck 14 has an interlocking three-jaw chuck structure that holds three chuck claws 15, 15, 15 that move synchronously on the main body 14 at equal intervals in the circumferential direction. It is.

16 is an arm mechanism, 17 is an arm drive mechanism, 1
8 is a rotation angle detector, 19 is a control device, and these elements 16 to 19 constitute the chuck slip detection device according to the present invention.

As shown in FIGS. 3 and 4, the arm mechanism 16 is generally composed of a pair of rotating arms 20, 20 and a pair of rotating shafts 21, 21. The rotation arms 20, 20 each have a rotation support shaft 21.
It is fixed to each rotation support shaft 21,
21 is a bearing 22, 22 on the standing wall 7 of the base 1.
The arm 20 is rotatably supported by the arm 20, thereby allowing each arm 20 to rotate. The rotation of each arm 20 allows the free end portion to come into contact with an eccentric portion (here, a crank pin) W of the workpiece W.

The arm drive mechanism 17 includes a pair of pinion gears 2
3, 23, a rack 24, and a cylinder device 25. Each pinion gear 23 is fixed to each rotating support shaft 21, and its teeth face each other at intervals. The rack 24 is arranged between these pinion gears 23, 23, and a rack part 26 is formed on the side facing each pinion gear 23, and one rack part 26 has a tooth on one pinion gear 23. The other rack portion 26 is connected to the other pinion gear 2.
3, and as the rack 24 reciprocates, the pair of rotating arms 20, 20 rotate synchronously. This results in
The center position between both rotating arms 20, 20 is prevented from shifting. Note that the pair of pinion gears 23, 23 may be meshed with each other, and the rack 24 of one of them may be meshed. 27 is a cylinder of the cylinder device 25, and 28 is the same piston rod. The rack 24 is configured to constitute a part of this piston rod 28, and is reciprocated by the power of this cylinder device 25. With that power, the rotating arms 20, 20 move to the eccentric portion W when the workpiece W is not gripped by the chuck 6.
On the other hand, when the workpiece W is gripped by the chuck 6, the workpiece W cannot be rotated, but instead rotates until it hits the eccentric part W and then stops. There is. That is, here, the rotation of the pair of rotating arms 20 in the direction approaching the eccentric portion W (direction of arrow C in the figure) is defined as normal rotation, and the rotation in the opposite direction (direction of arrow D in the figure) is defined as reverse rotation. Then, as will be described later, the pair of rotating arms 20, 20 are moved twice: before the workpiece W is processed, before it is gripped by the chuck 6, and after the workpiece W is processed, before the gripping action by the chuck 6 is released. Crossing and turning in the right direction. First, during the first normal rotation, both rotating arms 20, 20 rotate until they come into contact with the eccentric part W, that is, one rotating arm 20 eccentrically rotates earlier than the other rotating arm 20. When it comes into contact with the part W, it is pushed and rotated while rotating the workpiece W, and as shown in FIG. 3, the center position between both rotating arms 20, 20 and the center of the eccentric part W match Then, the other rotating arm 20 also comes into contact with the eccentric portion W, and the rotation of both rotating arms 20, 20 is stopped.
Since each part of the workpiece W is positioned in the rotational direction, and the center position between the two rotating arms 20, 20 does not change depending on the rotation angle,
This makes it possible to perform positioning in the rotational direction corresponding to workpieces of various sizes. Next, 2
During the second normal rotation, both rotating arms 20, 20 rotate until at least one rotating arm 20 comes into contact with the eccentric portion W. In other words, one rotating arm 20 rotates until the eccentric portion W contacts Both rotating arms 20, 20 rotate until they come into contact with each other. In other words, when one rotating arm 20 comes into contact with the eccentric portion W and stops, the other rotating arm 20 also rotates with the eccentric portion W.
It will stop even if it is not in contact with the In this case, it is possible to find a difference between the rotation angle during the first normal rotation and the rotation angle during the second rotation, as indicated by the symbol M as shown in FIG. A spacer 33, which is softer than the work W, is fixed to the free end of each rotating arm 20 that comes into contact with the eccentric portion W, and the spacer 33 prevents the work W from being damaged.

The rotation angle detector 18 consists of a rotary encoder, 29 is its body, and 30 is a rotation input shaft. The body 29 is fixed to the surface of the upright wall 7 opposite to the facing surface 13 via a bracket 31. The rotation input shaft 30 is connected to one rotation support shaft 21 via a connector 32, and is adapted to detect the rotation angle of one rotation arm 20.
The output signal of this rotation angle detector 18 is
9 is now entered.

The control device 19 controls the arm drive mechanism 1 so as to rotate the pair of rotating arms 20, 20 in the forward direction twice as described above.
7, captures rotation angle data from the output signal of the rotation angle detector 18 during each normal rotation, and compares the rotation angle data during each normal rotation with each other. What is shown in FIG. 5 is the control flow, which also controls the entire processing system.

Next, a cycle in the processing system will be explained with reference to FIG. 5.

The work W is first placed on the pedestals 2 and 3,
The actuating mechanism 4 is then actuated, and the pressing pins 5, 5 are pressed against each end and positioned in the axial direction;
The axial position is fixed. Subsequently, the pair of rotating arms 20, 20 rotate in the normal direction, and the rotational direction position of each part of the workpiece W is determined, and the rotation angle data X of the rotating arm 20 during this normal rotation is taken in. Once stored in memory.

When the storage in the memory is completed, the chuck 6 is activated, the end of the work W is grabbed, and the rotational position of each part is fixed.Then, the rotating arms 20, 20 are reversed, and the workpiece W is moved into the working space of the machine tool. is removed from the machine and one half of the holes H, H, ... are machined by this machine tool, and then the operating mechanism 4
It is rotated 180 degrees, the other half is machined and penetrated, and the drilling of holes H, H, ... is completed.

When the drilling of the holes H, H, .

First, it is determined whether the rotation angle data X and Y have the same value. Here, if it is determined that they are the same, the clamping jig performs an unclamping operation, and the workpiece W is sent to the next process.
When the cycle is completed, on the other hand, if it is determined that they are different, it is determined whether the difference between the rotation angle data X and Y is within a tolerance value. Here, if it is determined that it is within the allowable range, the clamp jig performs an unclamping operation, and the workpiece W is sent to the next process and the workpiece W is sent to the next process. The cycle ends. If it is determined that it is not within the allowable range, it will be displayed as a processing defect using an abnormality indicator lamp attached to the control panel, etc.
The cycle is interrupted to prevent the workpiece W from being sent to the next process.

Although the embodiments have been described in detail above, the present invention also includes the following concepts.

(1) Applicable machining systems for shaft parts include, in addition to crankshaft hole-drilling systems, keyway machining systems for shaft parts, and processing systems for manufacturing shaft parts with eccentric parts.

(2) Rotating arms may be provided specifically for positioning the shaft parts in the rotational direction and detecting chuck slip.

(3) As the rotation angle detector, in addition to a rotary encoder, a rotation angle detector, a linear scale, etc. can be used. Note that when a linear scale is used, the amount of linear movement of the piston rod 28 in the linearly moving part of the arm drive mechanism 17, ie, the rack 24 or the cylinder device 25, is detected.

(Effects of the Invention) As described above, according to the present invention, chuck slip can be detected, so if this detection is performed before sending the shaft part to the subsequent process, it is possible to This has the effect of being able to prevent leakage into the process.

Furthermore, conventionally, the positioning of the shaft component in the rotational direction has been carried out by forming a reference surface at the eccentric portion of the shaft component and providing a reference block arranged so that this reference surface can be brought into contact with the rotation of the shaft component. This was done by appropriately adjusting the position and setting the dimensions of this reference block in advance and applying the reference surface to the reference block, but the medium-sized and medium-weight line was designed to handle shaft parts of various sizes. Because the blocks flow randomly, the reference block must be repositioned, trial cut, and adjusted each time the dimensions change, and the reference block must be removed from the machine tool workspace each time machining is performed. There were problems with work efficiency, such as not having to do anything. however,
According to the present invention, the eccentric portion of the shaft component is sandwiched between a pair of rotary arms that rotate in synchronization before machining, so that the shaft component can be moved by the power from the rotary arms. Since it can be rotated, it can be used to position each part of the shaft component in the rotational direction, and the center position between the pair of rotating arms remains constant regardless of the rotation angle, so it can be used for various purposes. Since it is possible to handle shaft parts of different dimensions, conventional positioning work can be eliminated, which leads to improved work efficiency and helps complete automation of the process.

[Brief explanation of drawings]

Fig. 1 is a front view of the main part of the shaft parts processing system according to the present invention, and Fig. 2 shows the left half along the line A-A and the right half along the line B-B with respect to the center line L. 3 is an explanatory diagram showing the operating state of the rotating arm when chuck slip has not occurred, and FIG. 4 is an explanatory diagram showing the operating state of the rotating arm when chuck slip has occurred.
FIG. 5 is a flowchart of the control contents of the control device shown in FIG. 1. 5...Press pin clamp jig, 6...chuck, 16...arm mechanism, 17...arm drive mechanism
Chuck slip detection device, 18... Rotating angle detector, 19... Control device, 20... Rotating arm.

Claims (1)

[Scope of Claims] 1. A shaft component machining system comprising a clamping jig that grips a part of a shaft component, which is a workpiece, with a chuck during machining and fixes the rotational direction position of each part of the shaft component, comprising: It is capable of coming into contact with the eccentric part of the part,
an arm mechanism including at least a pair of rotating arms that sandwich the eccentric portion when they come into contact; an arm drive mechanism that rotates the pair of rotating arms in synchronization; and the plurality of rotating arms. a rotation angle detector that detects at least one rotation angle among the above, and a rotation angle detector that controls the arm drive mechanism so as to bring the plurality of arms into contact with the eccentric portion before and after machining the shaft component; A chuck slip detection device for a shaft component machining system, comprising: means for acquiring data from the rotation angle detector at each time of contact; and comparison means for comparing the data at each time of contact.