JPS637268B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a device for setting the top clearance (gap between a piston and a cylinder head) of a cylinder in a reciprocating compressor or the like.

(b) Prior Art Figure 1 shows the main parts of a reciprocating compressor used in refrigerators and air conditioners. In the figure, 1 is a frame, 2 is an electric motor stator fixed to the frame 1, 3 is a rotor paired with the stator 2, and 4 is a crankshaft that is pivotally supported by the frame 1 and to which the rotor 3 is fixed. In the crank part 5 of the crankshaft 4, a piston 7 that reciprocates in a cylinder 6 is inserted through a cross slide pin 9 at a cylindrical part 8 formed at the base thereof so as to be perpendicular to the reciprocating direction. connected. The crank part 5 is inserted into the cylindrical part 8 through a long hole 10 (see FIG. 2 and below) provided along the longitudinal direction of the cylindrical part 8.
When the crank part 5 rotates, the cross slide pin 9 slides in the cylindrical part 8, and the piston 7 engages with the cross slide pin 9 in the cylinder 6.
The cross slide pin 9 slides therein in a direction perpendicular to the cross slide pin 9.

A constant problem in this type of compressor is the adjustment of the top clearance between the piston 7 and the cylinder head 11. In other words, since this top clearance is an important factor determining the capacity of the compressor, it must be made to exactly match the design value.

In the compressor having the structure described here, the position of the top surface of the piston 7 at the top dead center is automatically determined and cannot be changed, so this is dealt with by adjusting the mounting position of the cylinder 6. Specifically, a large bolt hole is made in the cylinder 6 through which the mounting bolt 12 is passed, and after moving the cylinder 6 to determine the position, tighten the bolt 12 to remove the cylinder 6.
This is to firmly fix the frame 1. Incidentally, a device that automatically performs such operations has already been proposed in Utility Model Application Publication No. 1057 of 1981. This device has a fairly complex configuration, but to summarize the operating steps, (a) fix the compressor frame (b) fix the piston at top dead center (c) move from the tip of the piston to the end of the cylinder The cylinder is tightened and fixed to the frame while measuring the distance to. The problem is that the piston must be constantly pushed up to top dead center, and a special positioning device is required for this purpose, and even if such a positioning device were available, it would be difficult to measure the top clearance, Alternatively, there was an unavoidable possibility that the piston would wobble during the process of moving the cylinder, resulting in inaccurate clearance settings.

(c) Object of the Invention The object of the present invention is to provide a top clearance setting device that is simpler than those proposed so far.

(d) Structure of the Invention In the present invention, a piston connected to a crank is moved in a cylinder temporarily fixed to a frame, and the distance from the top surface of the cylinder to the top surface of the piston is continuously measured. The minimum value of the measured values is the distance when passing the top dead center, that is, the top clearance, so calculate the difference between this value and the target top clearance value, and adjust the cylinder mounting position by that difference. After that, the cylinder is permanently fixed.

(E) Embodiment An embodiment will be described with reference to FIG. 2 and subsequent figures.
Note that the configuration of the compressor itself is the same as that described in the section of the prior art, so the same reference numerals as in FIG. 1 are used, and the explanation will be omitted.

In FIG. 2, the cylinder 6 is fixed to the frame 1 with bolts 12. However, the fixation in this case is temporary fixation with a weak tightening force, and the cylinder 6 can be moved by applying a certain amount of force. The cylinder 6 is temporarily fixed in a state where it is fully moved away from the crankshaft 4 by using the fitting margin of the hole through which the bolt 12 is passed. On the other hand, the crank portion 5 is set at an angle of approximately 30° before passing the top dead center. The positions of the cylinder 6 and the crank portion 5 are set in the previous step, and the operations shown in FIG. 2 and subsequent steps begin with clamping the frame 1 in this state.

In FIG. 2, the top clearance measuring device 13 is first pressed against the cylinder 6. Measuring device 13
consists of a reference plate 14 and a digital scale 15 fixed thereto; the reference surface 16 of the reference plate 14 is brought into contact with the top surface of the cylinder 6, and the probe 17 of the digital scale 15 is brought into contact with the top surface of the piston 7, respectively. The digital scale 15 transmits the amount of displacement of the probe 17 in the form of a digital signal to an arithmetic circuit 18 shown in FIG. Further, the reference plate 14 is connected to the cylinder 6 under the pressure of a spring 19 shown in the figure, and follows the movement of the cylinder 6. Reference numerals 20 and 21 denote a pair of left and right drive pins, which enter through openings at both ends of the cylindrical portion 8 and clamp the cross slide pin 9 therebetween.

In FIG. 3, the drive pins 20 and 21 move to the right in the figure while holding the cross slide pin 9, causing the crank part 5 to pass the top dead center and until the cross slide pin rotates about 30 degrees. Slide 9. At this time, the distance between the top surface of the cylinder 6 and the top surface of the piston 7 changes moment by moment, but this change is immediately read by the digital scale 15 and transmitted to the arithmetic circuit 18. The reading when the cylinder top surface and the piston top surface are closest to each other is the top clearance in this case, and the difference between this value _C1 and the target value Co is immediately calculated by the calculation circuit 18.

FIG. 4 shows a state in which the piston 7 has stopped after passing the top dead center, and the locking ram 22 descends and presses the counterbalance portion 23 of the crankshaft 4, thereby preventing the rotation of the crankshaft 4. Stop completely.

Next, as shown in FIG.
4 approaches the cylinder 6 from the same direction as the top clearance measuring device 13 and starts pushing the cylinder 6. Electric motor 25 driving ram 24 (Figure 9)
is based on the calculated value of the arithmetic circuit 18, and the cylinder 6 is adjusted by the difference between the actual top clearance value and the target value.
The ram 24 is driven so as to push. Since the digital scale 15 continues to measure, the reading is fed back to the arithmetic circuit 18 and the motor 2
5 can be monitored to ensure that it stops at the target position.

When the cylinder 6 has been moved, the torque wrench 26 tightens the bolt 12 as shown in FIG.
The cylinder 6 is firmly fixed to the frame 1.

Next, as shown in FIG. 7, the locking ram 22 is pulled up to release the crankshaft 4, and the forced displacement ram 24 is pulled away from the cylinder 6. Then, move the drive pins 20 and 21 to the left to make the piston 7 move past the top dead center again, and check that the top clearance reading _C2 at this time is equal to the target value Co or within the allowable range. Check. after that,
As shown in FIG. 8, the measuring device 13 and drive pins 20, 2
1 is separated from the cylinder 6 and cross slide pin 9, and the compressor is sent to the next process.

(F) Effects of the Invention In the present invention, the piston is moved inside the cylinder, the top clearance is measured during the movement process, and then the cylinder is moved from the temporarily fixed position in order to make the difference between the actual measurement value and the target value zero. Since the piston is shifted, there is no need to keep the piston at the top dead center position during the cylinder shifting process, no positioning means is required, and factors that make measurement unstable can be eliminated.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the main parts of a compressor to which the apparatus of the present invention is used. FIG. 2 and subsequent figures show one embodiment of the apparatus of the present invention, FIGS. 2 to 8 are partial sectional plan views explaining the general structure and operation of the apparatus, and FIG. 9 is a control system diagram. 1...Frame, 4...Crankshaft, 5
...Crank part, 6...Cylinder, 20, 21...
... Drive pin (means for causing the piston to move past the top dead center), 13 ... Measuring means, 16 ... Reference surface, 1
7...Probe, 18...Arithmetic circuit (means to calculate the difference between the actual measured value and target value of top clearance), 24...Forcible movement ram (means to shift the cylinder), 26...Torque wrench (means to shift the cylinder) means of fixing the book).

Claims (1)

[Scope of Claims] 1. Means for moving a piston connected to a crank so as to pass through the top dead center in a cylinder temporarily fixed to an equipment frame, a reference surface in contact with the top surface of the cylinder, and a means for moving a piston connected to a crank so as to pass through the top dead center; a measuring probe that comes into contact with the top surface of the top dead center and measures the top clearance when passing the top dead center; A top clearance setting device comprising: means for calculating the calculated value; means for shifting the cylinder and the frame so as to make the difference zero based on the calculated value; and means for permanently fixing the shifted cylinder to the frame.