JPH055953Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a roller pressurizing device for a vertical roller mill that crushes ores such as cement clinker and cement raw materials. This relates to the configuration of a hydraulic cylinder.

Background Art A vertical roller mill basically uses hydraulic cylinders or springs to apply a plurality of rollers arranged at intervals in the circumferential direction toward a table that is driven to rotate around a vertical axis. The object to be crushed is compressed and supplied to the center of the table, and is crushed and crushed between the table and the rollers.

In some prior art techniques, the rollers are configured to come into direct contact with the table when the layer of material to be crushed on the table runs out during operation.

In such prior art techniques, the rollers contact the table directly with great pressure, which often results in damage to the table and rollers.

Another prior art is shown in FIG. In this prior art, a table 2 having a vertical axis is provided in a housing 1, on which a roller 3 is arranged. An arm 5 is fixed to a support member 4 that supports the roller 3, and this arm 5 is supported by a pin 6 so as to be angularly displaceable at a fixed position. The arm 5 is connected to a piston rod 8 of a hydraulic cylinder 7 by a pin 9, and the cylinder 7 is connected to a piston rod 8 by a pin 10.
connected to a fixed position by. Table 2 is
It is rotated around a vertical axis by a motor 12 via a speed reducer 11 . The material to be crushed is supplied from the inlet chute 13, and this material is crushed and crushed between the table 2 and the rollers 3.
radially outwardly and is received by the pedestal 15.

A stopper 14 is provided to restrict the lowering position of the roller 3, so that even if the layer of material to be crushed is no longer on the table 2, the roller 3 is prevented from coming into direct contact with the table 2. A prior art having such a stopper 14 is shown in, for example, Japanese Utility Model Application Laid-Open No. 62-48436.

Problems to be Solved by the Invention In the prior art shown in FIG. , and shorter than the distance between the pins 6 and 9. Therefore, the load that the stopper 14 receives is greater than the pressing force of the roller 3 on the table 2. Furthermore, the roller 3 descends at a high speed when there is no longer a layer of material to be crushed on the table 2, causing the arm 5 to violently collide with the stopper 14. Therefore, the load that the stopper 14 receives reaches, for example, several hundred tons or more when the vertical roller mill becomes large-sized. Therefore, the structure of the stopper 14 itself and the surrounding structure to which the stopper 14 is attached must have great strength.

The purpose of this invention is to prevent direct contact between the table and rollers even when there is no object to be crushed between them, and to eliminate the need for a structure with unnecessarily high strength. It is an object of the present invention to provide a roller pressing device for a type roller mill.

Means for Solving the Problems The present invention is a vertical roller that presses a plurality of rollers arranged at intervals in the circumferential direction toward a table that is driven to rotate around a vertical axis using the suction pressure of a hydraulic cylinder. A roller pressurizing device for a type roller mill is provided with means for variably adjusting the vertical relative position of the piston of the hydraulic cylinder and the roller, and the table and the roller are directly connected when the piston of the hydraulic cylinder abuts the lowest end of the cylinder. This roller pressing device for a vertical roller mill is characterized in that a slight gap exists between the table and the rollers to prevent contact.

Effect According to the present invention, a hydraulic cylinder is used to press the roller toward the table with its suction pressure, and during crushing operation, if there is no object to be crushed on the table,
The roller descends, but when the piston of the hydraulic cylinder that is pulling the roller reaches the lowest end of the cylinder, the roller no longer descends any further, and in this state there is a small gap between the table and the roller. Therefore, direct contact between the table and the rollers is prevented.

Moreover, when the piston of the hydraulic cylinder is in contact with the lowest end of the hydraulic cylinder, the hydraulic cylinder receives the weight of the roller and the member supporting it.
4 (see FIG. 4) becomes unnecessary, the structure becomes simpler, and it becomes possible to reduce a large amount of manufacturing cost.

Embodiment FIG. 1 is a sectional view of an embodiment of the present invention.
A table 18 is provided within the cylindrical housing 17 and is driven to rotate around a vertical axis. This table 18 is moved by the reducer 5 by the motor 19.
Rotationally driven via 4.

A plurality of rollers 20 are arranged above the table 18 at intervals in the circumferential direction. This roller 2
0 has a rotation axis extending in the radial direction of the table 18, and is rotatably supported by the support member 21. The support member 21 is fixed to an arm 22, and this arm 22 is attached by a pin 23 to a column 24 erected at a fixed position so as to be angularly displaceable. Arm 22
In connection with this, a roller pressing device 25 is provided that presses the roller 20 toward the table 18.

A classifier 26 is provided within the housing 17 above the table 18 and rollers 20. The crushed and crushed material between the table 18 and the rollers 20 is blown up by the air flowing upward from the space 27 between the outer peripheral surface of the table 18 and the inner peripheral surface of the housing 17. , the fine powder is discharged from a duct 28 by a classifier 26. The coarse powder classified by the classifier 26 and the material to be crushed from the newly inserted chute 29 fall onto the table 18 from the chute 30 provided in the center directly above the table 18, and are crushed and crushed. Ru.

FIG. 2 is a sectional view showing the structure of the roller pressure device 25. As shown in FIG. Piston rod 33 of hydraulic cylinder 32
is connected to a rod 35 via a turnbuckle 34. This rod 35 is connected to the arm 2 by means of a pin 36.
2. Pin 36 is parallel to pin 23 and perpendicular to the axis of rotation of roller 20.

In the turnbuckle 34, an end of the piston rod 33 and an end of the rod 35 are provided with external threads in opposite directions, into which a nut 37 is screwed.

The hydraulic cylinder 32 is connected by a clevis pin 38 to a bracket 39 provided in a fixed position. The turnbuckle is arranged so that there is a slight gap, for example, at least a few mm, between the table 18 and the roller 20 when the piston 40 of the hydraulic cylinder 32 is in contact with the lowermost end 41 of the cylinder 32. 34 is adjusted. Detector 42 attached to the hydraulic cylinder 32
is provided close to the piston rod 33 and detects the position of the piston rod 33 immediately before the piston 40 contacts the lowermost end 41 of the cylinder 32.

The hydraulic cylinder 32 is a so-called double-acting cylinder in this embodiment, and has hydraulic chambers 43 and 44.

FIG. 3 shows the hydraulic circuit associated with the hydraulic cylinder 32. Pressure oil from the pump 45 is connected from a conduit 48 to the hydraulic chamber 43 of the hydraulic cylinder 32 via a spring center type three-position electromagnetic switching valve 46, and further via a check valve 55 and a conduit 47.
The pipe line 47 is connected to the pipe line 5 through a spring-off center type two-position electromagnetic switching valve 50 via a pipe line 49.
1 is connected to the tank. Another chamber 44 of the hydraulic cylinder 32 is connected to the tank via a line 53. The hydraulic cylinders 32 for each of the plurality of rollers 20 are connected in parallel.

During the operation for crushing the material to be crushed, the switching valve 50 is in the position Q1, and the switching valve 46 is switched from the rest position P1 to the position P2, thereby supplying pressure oil to the chamber 43 of the hydraulic cylinder 32. As a result, the roller 20 can be pressurized by the suction pressure of the cylinder 32. Therefore, the object to be crushed on the table 18 can be crushed and crushed by the rollers 20.

When the object to be crushed is no longer interposed between the table 18 and the rollers 20, the piston 40 moves downward in FIG. cylinder 32
approaches the lowest end 41 of. Immediately before the piston 40 abuts the lowermost end 41 , this is detected by the detector 42 . Therefore, the control circuit 5
2 switches the switching valve 50 from position Q1 to position Q2. Line 49 is therefore connected to the tank via position Q2. Therefore, the hydraulic cylinder 32
The pressure in chamber 43 drops immediately. This prevents the piston 40 from violently hitting the lowermost end 41 of the hydraulic cylinder 32. When the piston 40 is in contact with the lowermost end 41, there is a slight gap between the table 18 and the roller 20 as described above. Therefore, the table 18 and the roller 20 do not come into direct contact, and both
8.20 damage is prevented.

By providing the turnbuckle 34, when the table 18 and roller 20 become worn, the mutual gap between them can be readjusted.

In the above embodiment, the table 18 and the roller 20
Although the turnbuckle 34 is used to adjust the gap, in other embodiments, the turnbuckle may be replaced by holding the shim with a flange and tightening the bolts, or by attaching a shim to the underside of the bracket 39 and tightening the bolts. Needless to say, any adjustment mechanism may be used.

Effects As described above, according to the present invention, when the piston of the hydraulic cylinder comes into contact with the bottom end of the cylinder, there is a slight gap between the table and the rollers, so that the table and rollers are not connected to each other. There is no direct contact, thus preventing damage to both.

Therefore, according to the present invention, material supply to the mill is temporarily interrupted when starting or stopping the vertical roller mill, when the material supply chute to the vertical roller mill is clogged, or when the material supply transport machine malfunctions. Even when there is no material on the table due to interruption, there is no direct contact between the roller and the table, and damage to the roller and table can be prevented.

Further, according to the present invention, since a means for variably adjusting the relative vertical position of the piston and roller of the hydraulic cylinder, such as a turnbuckle, is provided, there is no need to improve the accuracy of the hydraulic cylinder.
It becomes possible to accurately provide the gap, thereby easily improving the grinding accuracy of the vertical roller mill. Furthermore, even when the table and rollers become worn, the gap can be adjusted and set to an optimal value.

Moreover, as described in connection with the prior art described above, the present invention does not require a stopper for regulating the lowering position of the roller, and there is no need to adopt a structure having unnecessarily high strength.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an embodiment of the present invention, Fig. 2 is a sectional view of the roller pressurizing device 25, Fig. 3 is a hydraulic circuit diagram related to the hydraulic cylinder 32, and Fig. 4 is a sectional view of the prior art. It is. 17...Housing, 18...Table, 19
... motor, 20 ... roller, 21 ... support member, 22 ... arm, 25 ... roller pressure device,
26...Classifier, 32...Hydraulic cylinder, 34...
...Turnbuckle, 42...Detector.

Claims (1)

[Claims for Utility Model Registration] Rollers of a vertical roller mill that pressurizes a plurality of rollers arranged at intervals in the circumferential direction on a table that is rotationally driven around a vertical axis using the suction pressure of a hydraulic cylinder. The pressurizing device includes means for variably adjusting the vertical relative position of the piston of the hydraulic cylinder and the roller, so that the table and the roller do not come into direct contact when the piston of the hydraulic cylinder abuts the lowest end of the cylinder. A roller pressing device for a vertical roller mill, characterized in that a slight gap exists between the table and the rollers.