JPH02292148A - Phase dividing device in crank pin grinder - Google Patents

Abstract

PURPOSE:To carry out the phase division for a crank pin at an arbitrary angle by detecting the turning angle of a phase dividing motor by an encoder and controlling the turning angles of the motor and holding the phase dividing motor in stop state during the revolution of a main spindle. CONSTITUTION:In the grinding of a crank pin, main spindles 23 and 24 and a dividing shaft 40 are revolved at the equal revolution speed, and a phase dividing motor 48 is kept in stop state. While, in the phase dividing for the crank pin, the dividing shaft 40 is relatively revolved for the spindles 23 and 24 by the drive of the phase dividing motor 48, and the crank pin is phase- divided. The turning angle of the phase dividing motor 48 is detected by an encoder 49, and when the motor 48 is turned by a prescribed angle, the revolution is suspended.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a phase indexing device for a crankpin grinder.

BACKGROUND TECHNOLOGY> In general, a crank pin grinding machine for grinding the crank pin of a crankshaft that can perform phase indexing while the main shaft is rotating is disclosed in, for example, Japanese Patent Laid-Open No. 62-1507.
It is publicly known as described in Publication No. 0.

In this type of phase indexing device, a phase indexing shaft that indexes the phase of the crankpin is inserted into the main shaft, and this phase indexing shaft is connected to a phase indexing motor via a differential mechanism. While the spindle is rotating, the differential mechanism holds the phase indexing motor in a stopped state.
When the phase indexing motor is used to index the phase of the crank pin, the main shaft and the phase indexing shaft are rotated relative to each other, and a positioning device such as a knock pin is used to position the phase indexing shaft (crank pin) at a predetermined angular position. It is designed to be indexed.

Problems to be Solved by the Invention The above-mentioned phase indexing device requires a positioning device such as a knock pin to determine the phase of the crank pin, which not only complicates the structure of the phase indexing device, but also makes the structure of the phase indexing device complicated. However, there is a problem in that the phase indexing angle of the crank pin is limited, and phase indexing at an arbitrary angle cannot be performed.

Means for Solving the Problems> The present invention was made to solve the above-mentioned problems.A pair of headstocks are arranged facing each other on a table, and the spindles are rotated on the same axis by these headstocks. A chuck is attached to the end face of these main shafts to support the journal at an eccentric position in order to hold the crank pin of the crankshaft on the rotational axis of the main shaft, and A rotatable indexing shaft is provided, and an engaging portion that engages with one end of the crankshaft is provided at the tip of the indexing shaft,
In a crank pin grinding machine equipped with a phase indexing device for determining the phase of the indexing shaft, the phase indexing device includes:
a first gear meshing with a gear provided on the main shaft;
A second gear is provided relatively rotatably on the same axis as the first gear and meshes with the gear provided on the indexing shaft, and the second gear is connected to the second gear via a differential. The motor is equipped with a phase indexing motor, a control device for controlling the rotation of the phase indexing motor, and an encoder for detecting the rotation angle of the phase indexing motor and feeding it back to the control device.

<Function> With the above configuration, when grinding the crank pin, the main shaft and the indexing shaft are rotated at the same rotational speed, and the phase indexing motor is held in a stopped state. On the other hand, when determining the phase of the crank pin, the index shaft is rotated relative to the main shaft by driving the phase index motor, and the phase of the crank pin is determined. The rotation angle of the phase indexing motor is detected by an encoder, and the rotation is stopped when the motor is rotated by a predetermined angle.

Example Embodiments of the present invention will be described below based on the drawings.

In FIG. 1, reference numeral 10 indicates a bed, and a grindstone head 1l and a table 12 are placed on the bed 10 so as to be slidable in directions perpendicular to each other. The grindstone head 11 is the feed motor 1
It is moved forward and backward with respect to the table 12 by a ball mechanism (not shown) driven by reference numeral 3. A whetstone shaft 15 is rotatably supported on the whetstone head l1, and a whetstone wheel 17 that is rotationally driven by a whetstone drive motor 16 is attached to this whetstone shaft 15.

A pair of left and right headstocks 21, 22 are arranged facing each other on the table 12, and a main spindle 23.
24 are rotatably supported on the same axis. A chuck 25.26 is attached to the tip of each main shaft 23.24, and the journal J1. Journal receivers 27, 28 are provided to support J2. chuck 2
Clamp arms 29 and 30 for clamping the journals Jl and J2 are also rotatably attached to 5.26,
One end of these clamp arms 29, 30 is connected to the chuck 25.
．． It is connected to a clamp cylinder formed at 26.

A spindle drive motor 36 is connected to the spindle 23 supported on one of the headstocks 21 via a gear mechanism 35, and the driving force of the spindle drive motor 36 is transmitted via an unillustrated synchronous shaft that connects both spindles. is transmitted to the main shaft 24, and both main shafts 23, 24
are designed to rotate synchronously. In addition, the main shaft 23
A gear 37 is fixed concentrically to the earth shaft 23 at the rear end.

On the other hand, an indexing shaft 40 is rotatably inserted through the axis of the main shaft 23, and a gear 41 is fixed to the rear end of the indexing shaft 40, as shown in FIG.

This gear 41 is a first gear rotatably supported on the headstock 2l.
It is meshed with the gear 42 of. A transmission shaft 43 is rotatably supported concentrically on the first gear 42, and this transmission shaft 43
A second gear 44 that meshes with the gear 37 is fixed to one end of the gear. An output member 46 of a known differential device 45 having a speed reduction function is coupled to one end of the first gear 42,
20 A phase indexing motor 48 installed on the headstock 21 is coupled to the input member 47 of the differential gear 45. The other end of the transmission shaft 43 is coupled to a member 50 of the differential device 45 that is capable of revolution and rotation. Further, an encoder 49 is connected to the phase indexing motor 48 to detect its rotation angle.

21 gears 37 that mesh with each other between the two axes mentioned above
and 44 and 41 and 42 are set so that the rotation speed of the index shaft 40 is the same as the rotation speed of the main shaft 230 during rotation of the main shaft 23, and at this time, the differential gear 45 rotates the phase index motor 48. is kept in a stopped state.

An index pin 51 is provided at the tip of the index shaft 40 and engages with a pin hole W1 formed in the end face of the journal J1, and the index pin 51 is pressed by a spring 52 so as to be movable forward and backward. .

On the other hand, the table 12 is reciprocated by a ball screw mechanism (not shown) driven by a feed motor 53 to index each crank pin to be ground at a position corresponding to the grinding wheel 17.

The feed motors 13 and 53 each have a drive circuit 60.
．． 61 is connected, and this drive circuit 60.61 is connected to a CPtJ (central processing unit) 63 of the numerical control device 62 via a pulse distribution circuit 64.65. This CPU 63 has an interface 67 and a memory 6.
6 is connected.

This interface 67 includes a grindstone drive motor 16,
The main shaft drive motor 36 and the phase indexing motor 48 are connected via mork control circuits 68, 69, and 70, respectively. A current detection circuit 71 is connected between the motor control circuit 70 and the phase indexing motor 48, and its output signal is input to the interface 67. Furthermore, the interface 67 is connected to an encoder 49 connected to the phase indexing motor 48 .

Next, the operation during phase indexing in the above configuration will be explained. Crankshaft W on both chucks 25 and 26
When a machining command is given with the journals Jl and J2 mounted, the phase indexing motor 48 is started and the indexing shaft 40 is aligned via the differential gear 45, second gear 42 and gear 41. It is rotated in the direction (positive direction). Due to this rotation of the indexing shaft 40, when the indexing pin 5 corresponds to the indexing hole Wl of the crankshaft W, the indexing pin 51 is engaged with the indexing hole W1, and the crankshaft W is integrated with the indexing shaft 40. The object starts to rotate. Phase indexing motor 48
When the encoder 49 detects that the phase indexing motor 48 has been rotated by a predetermined angle, the rotation of the phase indexing motor 48 is stopped. In this state, the clamp arm 29.30 is rotated by the clamp cylinder, and the journal J1. J2 is clamped. Subsequently, the phase indexing motor 48 is rotated in the opposite direction, and the indexing shaft 40 is reversed, but the rotation amount allowed for the indexing shaft 40 at this time is the same as that of the indexing bin 51 and the indexing hole W1. This is due to backlash in the gear system of the phase indexing device.

When the backlash and packlash are removed, the load current of the phase indexing motor 48 increases. The current increase at this time is detected by a current detection circuit, and when the load current exceeds a certain value, the phase indexing motor 48 is stopped, and the detection signal of the encoder 49 at this time is updated as the origin signal.

In this way, a specific crank pin on the crankshaft W is phased on the rotation axis of the main shaft 230. Thereafter, the main shaft drive motor 36 is driven, and grinding of the crank pin, which is phased on the rotational axis of the main shaft 23, is started.

When the grinding of the crank pin is completed, the main shaft 23 is stopped at a certain angular position, and then the clamp arm 2
9,30 was opened and journal J1. J2 is unclamped. When the journals Jl and J2 are unclamped, the phase indexing motor 48 is rotated in the opposite direction again.

The rotation of the phase indexing motor 48 is detected by an encoder 49, and when the rotation of the phase indexing motor 48 has been rotated by a predetermined angle, for example, 1800 degrees, the rotation of the phase indexing motor 48 is stopped and servo-locked. At this time, the origin of the encoder is the index bin 51.
Since the setting eliminates the play between the index hole W1 and the backlash of the gear system, the crankshaft W can be rotated at a predetermined angle with high precision without being affected by the play and backlash of the gear system. phase indexing becomes possible.

Thereafter, the crankshaft W is clamped in the same manner as described above, and the crank pin is ground.

Effects of the Invention> As described above, according to the present invention, by providing two sets of gears with different gear ratios and a differential device, the phase indexing motor can be held in a stopped state while the main shaft is rotating. It became like this,
Moreover, since the rotation angle of the phase indexing motor is detected by an encoder and the rotation angle of the phase indexing motor is controlled, the conventional positioning device for determining the phase is not required, simplifying the configuration. This has the effect that it is possible to achieve this, and also to index the phase of the crank pin at any angle.

[BRIEF DESCRIPTION OF THE DRAWINGS] The drawings show embodiments of the invention. Fig. 1 is an overall view of a numerically controlled crank pin grinder, Fig. 2 is a block diagram of the numerically controlled crank pin grinder, and Fig. 3 is a block diagram of the numerically controlled crank pin grinder. FIG. 3 is an enlarged cross-sectional view of the main part of FIG. 2 showing the phase indexing device. 11... Grindstone stand, 12... Table, 21.22.
... Headstock, 23.24... Main spindle, 25.26...
Chuck, 36... Main shaft drive motor, 40... Indexing shaft, 37, 41, 42. 44... Gear, 45...
Differential device, 48... Phase indexing motor, 49... Encoder, 62... Numerical control device.

Claims (1)

[Claims] (1) A pair of headstocks are arranged facing each other on the table, a main spindle is supported on these headstocks so as to be rotatable on the same axis, and a crank pin of a crankshaft is attached to the end face of these main spindles so that the rotation axis of the main spindle is centered. A chuck is installed to support the journal at an eccentric position so as to hold it above, and an indexing shaft that can rotate relative to the main shaft is provided on the axis of the main shaft, and the tip of this indexing shaft is engaged with one end of the crankshaft. In the crankpin grinding machine, the crankpin grinding machine is provided with a phase indexing device that determines the phase of the indexing shaft, and the phase indexing device has a first gear that meshes with a gear provided on the main shaft. a gear; a second gear that is relatively rotatably provided on the same axis as the first gear and meshes with the gear provided on the indexing shaft; and a differential gear connected to the second gear. A crank pin grinder comprising: a phase indexing motor connected to each other; a controller for controlling rotation of the phase indexing motor; and an encoder for detecting a rotation angle of the phase indexing motor and feeding it back to the controller. Phase indexing device on the board.