JPH0947680A - Roller type grinding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a roller type grinding device in which vibration of a roller and a grinding part is absorbed and reduced and violent self-excited vibration is not caused even when slippage is caused in the roller and material to be ground. SOLUTION: A flow resistance-giving means for variably giving resistance to flow of a hydraulic medium 26 e.g. a flow rate control valve 23 is disposed on the pipeline 27 of the hydraulic medium 26 of a pressure mechanism which pressurizes a roller 2 on a grinding ring l. For example, number of vibration of a grinding part is detected by a sensor 25 fitted to a roller bracket 3 or the like. Resistance of the flow rate control valve 23 is controlled so as to become resistance capable of most absorbing and reducing vibration of the grinding part in the number of vibration.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roller-type crushing device, and more particularly to a roller-type crushing device suitable for absorbing and reducing intense self-excited vibration generated during crushing.

[0002]

2. Description of the Related Art The entire structure of a conventional roller type crushing device is shown in FIG.

The yoke 10 is rotatably mounted on the output shaft of the speed reducer 11, and an annular crushing ring 1 is fixed on the yoke 10. Crushing ring 1
In the upper recess, three sets of rollers 2 supported by a roller bracket 3 so as to be rotatable by a shaft 5 and bearings are installed at equal intervals.

A groove into which the pivot pin 4 is inserted is formed in the upper portion of the roller bracket 3 and the lower surface of the pressure frame 9, and the roller bracket 3 and the roller 2 are crushed by the pressure frame 9 via the pivot pin 4 by a crush ring. The roller 2 is pressed onto the roller 1 so that the roller 2 does not fall.

A pivot arm 12 is attached to the pressure frame 9, and the other end of the pivot arm 12 is connected to a loading rod 13 fixed to a hydraulic cylinder 17.

When the input shaft of the speed reducer 11 is rotated by the motor, the yoke 1 attached to the output shaft of the speed reducer 11 is rotated.
0, and the crushing ring 1 fixed to the yoke 10 rotates. At this time, the hydraulic cylinder 17 pulls the loading rod 13, and this pulling force pushes the pressing frame 9 downward via the pivot arm 12, and the pressing frame 9 pushes the pivot pin 4 and the roller bracket 3 together. The roller 2 is pressed against the crushing ring 1 via.

The material to be crushed (for example, coal) is dropped from the supply pipe 14 at the upper center of the housing 19, sandwiched between the roller 2 and the crushing ring 1, and crushed by the crushing action. The crushed object to be crushed (for example, pulverized coal) is blown up by hot air, passes through the classifier 15 to the outlet pipe 16 for particles having a predetermined particle size, and to the crushing portion for particles having a larger particle size, and crushes again. It is structured to be.

FIG. 9 shows a side view of a pressure mechanism of a conventional roller type crusher.

A roller 2 which is rotatably supported by a shaft 5 and a bearing on a roller bracket 3 is installed in the hollow portion on the crushing ring 1, and an object to be crushed 18 is crushed.
Is designed to be crushed. A groove into which the pivot pin 4 is inserted is formed in the upper portion of the roller bracket 3 and the lower surface of the pressure frame 9, and the roller bracket 3 and the roller 2 are pressed onto the crushing ring 1 by the pressure frame 9 via the pivot pin 4. Therefore, the roller 2 is prevented from falling.

A pivot arm 12 is attached to the pressure frame 9, and the other end of the pivot arm 12 is connected to the loading rod 13. The other end of the loading rod 13 is a cylinder 20.
It is connected to the piston 21 inside.

A pipe line 27 is connected to the cylinder 20. By supplying a hydraulic medium 26 through the pipe line 27 with a pump, the loading rod 13 can be pulled and the roller 2 can be pressed onto the crushing ring 1. ing. Further, the accumulator 22 is attached to the pipe line 27 so that the pressure fluctuation of the hydraulic medium 26 can be absorbed to some extent.

[0012]

However, the above-mentioned conventional device does not take vibrations into consideration, and there is a problem that very strong self-excited vibrations are generated during pulverization.

As shown in FIG. 9, the roller type crusher has a structure in which the crushed object 18 is crushed by the crushing ring 1 and the roller 2.

In the conventional roller type crushing device, when the roller 2 and the object to be crushed 18 slip during crushing, the roller 2 and the crushing part may vibrate violently in the vertical direction due to stick-slip or corrugation phenomenon.
When a slip occurs between the roller 2 and the object to be crushed 18 in the direction perpendicular to the direction of rotation of the roller 2, a stick-slip phenomenon occurs in which the shaft 5 and the bearing serve as springs, and the roller 2 vibrates violently in the vertical direction.

Further, the roller 2 and the object to be crushed 18 are
Slipping in the direction of rotation causes the layer of the object to be crushed 18 immediately below the roller 2 to collapse, which creates unevenness on the object to be crushed 18, and the roller 2 rolls on the unevenness, so that the vibration is self-excited. A growing corrugation phenomenon occurs.

Since the frequency of such self-excited vibration becomes the natural frequency of the crushing section and is extremely high, if the self-excited vibration occurs, the parts of the crushing section will be damaged or the crusher will be operated. There was a problem that I could not continue.

It is an object of the present invention to provide a roller type crushing device which absorbs and reduces vibrations of the roller and the crushing portion even when slip occurs between the roller and the crushed object and does not cause severe self-excited vibration. is there.

[0018]

The above object is to provide a flow resistance imparting variable resistance to the flow of the hydraulic medium to a hydraulic medium conduit (hydraulic pipe) of a pressurizing mechanism for pressurizing a roller to a crushing ring. Means, for example, a flow control valve is provided, and the frequency of the crushing section is detected by a sensor attached to, for example, a roller bracket, and the flow resistance is set so that the resistance value is the most capable of absorbing and reducing the vibration of the crushing section at this frequency. This is achieved by controlling the resistance value of the applying means.

[0019]

When the roller and the crushing section vibrate, the piston of the pressurizing mechanism that presses the roller also vibrates, and the hydraulic medium in the cylinder and the pipeline also vibrates accordingly.

In the roller type crushing device according to the present invention, the flow resistance applying means for applying a resistance to the flow of the hydraulic medium is provided in the pipeline of the hydraulic medium. By absorbing the vibration energy by the flow resistance applying means, It is possible to reduce vibration of the roller and the crushing section.

Further, when the particle size or thickness of the crushed object changes, the spring constant of the crushed object also changes, so the vibration characteristics such as the natural frequency of the crushed part also change, and the vibration of the crushed part accordingly. The flow resistance value that maximizes the amount of energy absorbed will also change.

In the roller type crushing device according to the present invention, the frequency of the crushing section is detected, and the flow resistance applying means is controlled so that the resistance value at which the vibration of the crushing section can be absorbed and reduced is the maximum. Therefore, it is possible to absorb and reduce the vibration even when the spring constant of the object to be crushed is changed, and the vigorous self-excited vibration does not occur in the crushing device.

[0023]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic view of a main part of a roller type crushing apparatus according to the first embodiment of the present invention.

A roller 2 which is rotatably supported by a shaft 5 and a bearing on a roller bracket 3 is installed in the hollow portion on the crushing ring 1, and an object to be crushed 18 is crushed.
Is designed to be crushed. A groove into which the pivot pin 4 is inserted is formed in the upper portion of the roller bracket 3 and the lower surface of the pressure frame 9, and the roller bracket 3 and the roller 2 are pressed onto the crushing ring 1 by the pressure frame 9 via the pivot pin 4. Therefore, the roller 2 is prevented from falling.

A pivot arm 12 is attached to the pressure frame 9, and the other end of the pivot arm 12 is connected to the loading rod 13. The other end of the loading rod 13 is a cylinder 20.
It is connected to the piston 21 inside.

A pipe line 27 is connected to the cylinder 20, and a hydraulic medium 26 is supplied by a pump through the pipe line 27 to pressurize the piston 21, pull the loading rod 13, and set the roller 2 on the crushing ring 1. It can be pressed against. A flow rate control valve 23 and an accumulator 22 are attached to the pipe line 27, and the pressure medium 26 is opened by opening and closing the flow rate control valve 23.
It is possible to change the flow resistance value of a wide range. The hydraulic medium 26 that has passed through the flow rate control valve 23 can be stored in the accumulator 22.

A sensor 25 such as an accelerometer is attached to the roller bracket 3 so that the magnitude of the acceleration of the crushing section and the vibration frequency can be monitored. The output signal of the sensor 25 is input to the control device 24, and the control device 24 can change the flow resistance value of the hydraulic medium 26 by controlling the opening degree of the flow control valve 23 according to the acceleration or vibration frequency of the crushing section. It is like this.

In the roller type crushing device according to the present invention, the flow control valve 23 is provided in the hydraulic line 27 as means for giving flow resistance to the hydraulic medium, and the flow resistance value is set to an optimum value. It is possible to absorb and reduce the vibration of the crushing section.

Further, if the particle size or thickness of the object to be ground 18 changes and the spring constant of the object to be ground 18 changes accordingly, the flow resistance value capable of absorbing and reducing the vibration of the crushing part changes.

In the roller type crushing device according to the present invention, the acceleration and vibration frequency of the crushing part are monitored, and the flow rate control valve 23 is controlled by the control device 24 so that the resistance value becomes an optimum value according to the vibration frequency of the crushing part. By controlling the
Even if the spring constant of No. 8 changes, it is possible to always absorb and reduce the vibration of the crushing section.

First, it will be described that the roller type crushing device according to the present invention can absorb and reduce the vibration of the crushing section.

In FIG. 1, when the roller 2 and the object to be crushed 18 slip, and the roller 2 vibrates violently in the vertical direction due to stick-slip or corrugation phenomenon,
Along with this, the roller bracket 3, the pressure frame 9,
The pivot arm 12, the loading rod 13, and the piston 21 also move vertically.

When the piston 21 in the cylinder 20 moves up and down, the hydraulic medium 26 in the cylinder 20 flows out / in from the cylinder 20. Along with this, the hydraulic medium 26 in the pipe line 27 also moves, the hydraulic medium 26 passes through the flow rate control valve 23, and flows out / flows into the accumulator 22.

The flow control valve 23 functions as a flow resistance for the hydraulic medium 26, and the flow resistance value of the hydraulic medium 26 can be changed by adjusting the opening of the flow control valve 23. By properly setting this flow resistance value, it is possible to damp and absorb the severe vibration of the crushing section.

FIG. 2 is a diagram showing the results of examining the vibration absorption reduction effect when the flow resistance value of the hydraulic medium 26 is changed by changing the opening degree of the flow control valve 23.

The horizontal axis represents the flow resistance value R, and the flow control valve 2
The flow rate Q of the hydraulic medium 26 passing through the valve 3, the pressure P ₁ in the cylinder 20 and the pipe 27, and the pressure P ₂ in the accumulator 22 have the following relationship.

Q = (P ₁ −P ₂ ) / R (1) Further, the vertical axis represents the magnitude of vibration displacement when the roller 2 is forcibly excited in the vertical direction at the natural frequency. When self-excited vibration occurs in the crushing device, its frequency becomes the natural frequency of the crushing unit, so it is necessary to absorb and reduce the vibration at the natural frequency.

As shown in FIG. 2, when the flow resistance value is changed, the vibration displacement amount at the natural frequency of the roller 2 also changes, and the flow resistance value with the smallest vibration displacement amount, that is, the vibration absorption reduction effect is the largest. There is an increasing flow resistance value.

In FIG. 2, the region R _{A to} R _{B is} a region in which the flow resistance value is too small, and the hydraulic medium 26 flows through the flow control valve 23 without resistance and flows into the accumulator 22, so that the roller 2 and the crushing unit. It is not possible to absorb and reduce the vibration of.

The region of R _{D to} R _{E is} a region where the flow resistance value is too large, and in this case, the hydraulic medium 26 hardly passes through the flow control valve 23. If the hydraulic medium 26 does not pass through the flow control valve 23, the vertical movement of the roller 2 causes the shaft 5, the pivot pin 4, the loading rod 13,
Since the hydraulic medium 26 vibrates as an elastic body, the vertical movement of the roller 2 also grows, and the vibration cannot be absorbed and reduced.

The region of R _{B to} R _{D is} a region of flow resistance value capable of absorbing and reducing vibration. In this case, the flow of the hydraulic medium 26 generated by the vertical movement of the roller 2 and the piston 21 can efficiently absorb energy by the flow resistance of the flow control valve 23, whereby the vertical movement of the roller 2 does not grow, It is possible to absorb and reduce vibration.

R _C is the point where the vibration can be absorbed and reduced most, and if the flow resistance value of the flow control valve 23 is set to R _C ,
The vibrations of the roller 2 and the crushing section can be absorbed and reduced most, whereby the occurrence of self-excited vibration can be prevented.

Next, the roller type crushing device according to the present invention is
The reason why the vibration can be absorbed and reduced even if the particle diameter and the thickness of the crushed object 18 change and the spring constant of the crushed object 18 changes will be described.

The object 18 to be crushed has a particle size of about several tens of millimeters and is crushed by the roller 2 and the crushing ring 1 to finally have a particle size of about several microns.
Therefore, the characteristics of the object to be crushed 18, particularly the spring characteristics that significantly affect the vibration characteristics of the crushed portion, are constantly changing.

Further, the characteristics of the crushed object 18 also greatly differ depending on the type (for example, in the case of coal, the type of coal and the place of origin). Therefore, the vibration characteristics of the crushing section are also changing every moment.

FIG. 3 shows the relationship between the natural frequency of the crushing section and the spring constant of the object to be crushed.

When the spring constant of the crushed object 18 increases and the crushed object 18 becomes hard, the natural frequency of the entire crushing section increases.

FIG. 4 shows the effect of the spring constant of the crushed material on the relationship between the vibration absorption reduction effect and the flow resistance.

As can be seen from this figure, as the spring constant of the object to be crushed 18 increases, that is, the natural frequency of the crushing part increases, the flow resistance value at which the vibration absorption reducing effect is maximized decreases.

FIG. 5 shows the relationship between the flow resistance value that maximizes the vibration absorption effect and the natural frequency.

As can be seen from this figure, in order to always obtain the maximum vibration absorption effect and prevent the occurrence of self-excited vibration,
It is necessary to change the flow resistance value of the hydraulic medium 26 according to the change of the spring constant of the crushed object 18, that is, the change of the natural frequency.

In the roller type crushing device according to the present invention, as shown in FIG.
Since the frequency of the crushing section can be monitored by the sensor 25 shown in FIG. 2 and the flow control valve 23 can be controlled by the control device 24, the flow control valve is always controlled so that the flow resistance value maximizes the vibration absorption effect. It is possible to control 23.

That is, the relationship shown in FIG. 5 is stored in advance in the control device 24, the natural frequency of the crushing section is known from the frequency of the crushing section measured by the sensor 25, and from the relationship shown in FIG. Even when the spring constant of the object to be crushed 18 changes, the flow resistance value that maximizes the vibration reduction effect is determined at the natural frequency, and the flow control valve 23 is controlled to have this resistance value. The maximum vibration absorption effect can be obtained, and the occurrence of self-excited vibration can be prevented.

As described above, according to the roller type crushing device of the present invention, even when the roller 2 and the object to be crushed 18 slip, the vibration of the roller 2 and the crushing portion can be absorbed and reduced. Therefore, violent self-excited vibration does not occur.

FIG. 6 is a schematic view of the essential parts of a roller type crushing apparatus according to the second embodiment of the present invention.

In the second embodiment shown in FIG. 6, a sensor 25 for monitoring the vibration frequency of the crushing section is provided with a pressure frame 9.
It is attached to. Since the sensor 25 is provided for monitoring the predominant frequency of the crushing unit, it does not necessarily have to be attached to the roller bracket 3, and the same operation is obtained no matter where it is attached to the crushing unit. FIG. 7 is a configuration diagram of the main parts of a roller type crushing device according to a third embodiment of the present invention.

The third embodiment shown in FIG. 7 is applied to a crushing device in which rollers are rotatably fixed to a casing.

In this type of crushing apparatus, the roller 28 is fixed to a bracket 32 so as to be rotatable by a shaft 30, and the bracket 32 is rotatable by a pin 34 on a support plate 33 fixed to a casing 31. Is attached to.

A pressure rod 35 is attached to the bracket 32, and the other end of the pressure rod 35 is connected to a piston 36 housed in a cylinder 37.
By sending the hydraulic medium 38 into the cylinder 37, the roller 28 is pressed against the object to be crushed on the table 29.

Also in this embodiment, the flow rate control valve 39 and the accumulator 40 are attached to the pipe line 43, and the hydraulic medium 3 is opened and closed by opening and closing the flow rate control valve 39.
It is possible to change the flow resistance value of No. 8 over a wide range.

Further, a sensor 42 such as an accelerometer is attached to the bracket 32 so that the magnitude of the acceleration and the vibration frequency of the crushing section can be monitored. The output signal of the sensor 42 is input to the control device 41, and the control device 41 changes the flow resistance value of the hydraulic medium 38 by controlling the opening degree of the flow rate control valve 39 according to the acceleration and vibration frequency of the crushing section. You can do it.

The operation and effect of this embodiment are exactly the same as those of the first embodiment shown in FIG. 1, and the vibration of the crushing portion can be absorbed and reduced, and the severe self-excited vibration can be prevented.

[0064]

According to the present invention, the resistance of the flow of the hydraulic medium of the hydraulic device is made variable, and the resistance is made variable, so that even if a slip occurs between the roller and the object to be crushed, the roller and the crushing unit can be operated. It is possible to provide a roller-type crushing device that absorbs and reduces the vibration of No. 1 and does not generate severe self-excited vibration.

[Brief description of drawings]

FIG. 1 is a main part configuration diagram of a roller-type crushing device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between a vibration displacement amount of a crushing section and a flow resistance value of a hydraulic medium.

FIG. 3 is a diagram showing a relationship between a natural frequency of a crushing unit and a spring constant of a crushed object.

FIG. 4 is a diagram for explaining the influence of the spring constant of the object to be ground on the relationship between the vibration displacement amount of the grinding unit and the flow resistance value of the hydraulic medium.

FIG. 5 is a diagram showing the relationship between the flow resistance value of the hydraulic medium that maximizes the vibration absorption effect and the natural frequency of the crushing unit.

FIG. 6 is a main part configuration diagram of a roller-type crushing device according to a second embodiment of the present invention.

FIG. 7 is a main part configuration diagram of a roller-type crushing device according to a third embodiment of the present invention.

FIG. 8 is an overall configuration diagram of a conventional roller-type crusher.

FIG. 9 is a configuration diagram showing a pressure device of a conventional roller type crushing device.

[Explanation of symbols]

 1 Grinding Ring 2 Roller 19 Housing 20 Cylinder 21 Piston 23 Flow Control Valve 24 Control Device 25 Sensor 26 Hydraulic Medium 27 Pipeline

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroaki Kanemoto 6-9 Takaracho, Kure City, Hiroshima Prefecture Babkotsk Hitachi Ltd. Kure Factory

Claims (5)

[Claims] 1. A crushing roller is rotatably supported in a housing, crushing rollers are arranged at predetermined intervals along the crushing ring rotation direction, and a crushing roller is pressed onto the crushing ring using a hydraulic device. Then, in the roller type crusher for crushing the object to be crushed between the crushing ring and the crushing roller, in the middle of the hydraulic pipe supplying the hydraulic medium to the hydraulic cylinder provided with the piston that indirectly presses the crushing roller, A roller-type crushing device comprising flow resistance imparting means for imparting resistance to the flow of a hydraulic medium. 2. The roller type crushing device according to claim 1, wherein the flow resistance imparting means is composed of a flow control valve provided upstream of an accumulator mounted midway in the hydraulic pipe. apparatus. 3. The roller type crushing device according to claim 1, wherein the resistance value of the flow resistance applying means is variable. 4. The sensor according to claim 3, wherein a vibration state such as an acceleration or a displacement amount of the crushing portion is monitored, and a sensor for controlling the resistance value of the flow resistance applying means according to the vibration state is provided at an appropriate place. Roller type crushing device. 5. The roller type crushing device according to claim 4, wherein the object monitored by the sensor is the frequency of the crushing unit.