JPS6116841B2 - - Google Patents

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an electro-hydraulic servo valve device suitable for use in an electro-hydraulic material testing device, and in particular to a high-frequency electro-hydraulic servo valve device suitable for high frequency switching. Related to valve devices.

[Conventional technology]

As a conventional electrohydraulic servo valve device, there is one as shown in FIG. 1, and this servo valve device a is interposed between an oil pump b and an oil reservoir c, and an actuator d. By directly driving the pair of spool valves e and f together with the electrodynamic force generating mechanism h, the flow path from the oil pump b and the flow path leading to the oil reservoir c are alternately switched. A hydraulic load is alternately applied to both oil chambers of actuator d, so that actuator d generates an excitation force.

[Problem that the invention seeks to solve]

However, in this type of conventional electro-hydraulic servo valve device, when switching the hydraulic fluid at high speed, the flow rate of the hydraulic fluid supplied to the actuator d is not large, so most of it is used for contraction. As a result, the working oil pressure does not sufficiently act on both oil chambers of the actuator d, and as a result, there is a problem that the actuator d cannot generate sufficient excitation force.

By the way, when the above-mentioned hydraulic oil flow rate is increased, the hydraulic oil pressure can still be applied to both oil chambers of the actuator even after subtracting the contraction amount, so that the actuator d can generate an excitation force even in a high frequency range. However, in order to increase the flow rate of hydraulic oil in this way, it is sufficient to increase the diameter and displacement of the spool valve, as can be seen from the following equation.

Here, Q is the hydraulic oil flow rate, C is a constant, D is the diameter of the spool valve, x is the displacement of the spool valve, g is the gravitational acceleration, γ is the density of the oil, and ΔP is the metering edge in the spool valve. The differential pressure between the upstream hydraulic pressure and the downstream hydraulic pressure is shown, respectively.

However, with such conventional means, the weight of the spool valve increases and its displacement increases, so a very large force is required to excite the spool valve during high-speed switching. .

The present invention aims to solve these problems by making it possible to increase the supply flow rate of hydraulic fluid while keeping the amount of displacement of the spool valve small while being lightweight. It is an object of the present invention to provide a high frequency electrohydraulic servo valve device that can be operated satisfactorily even in a high frequency range.

[Means for solving problems]

Therefore, the high-frequency electro-hydraulic servo valve device of the present invention is interposed between a working fluid supply source, a working fluid reservoir, and a load member having two load parts, and is connected to each load part of the load member. A servo valve device that can alternately apply hydraulic pressure has an electromagnetic drive mechanism that can generate high-frequency driving force in response to high-frequency alternating current, and a pipe-shaped valve shaft that is reciprocated in the axial direction by the electromagnetic drive mechanism. and communication between the working liquid supply passage from the working liquid supply source and the first passage connected to one of the two load parts and the passage to the working liquid reservoir according to the reciprocating movement of the valve shaft. a plurality of first spool valves that alternately communicate between the reservoir flow path and the first flow path; When the reservoir flow path and the second flow path connected to the other of the two load parts are communicated with each other, the first spool valve connects the reservoir flow path and the first flow path. A plurality of second spool valves that communicate the working liquid supply flow path and the second flow path when they are in communication are arranged on the valve shaft at predetermined intervals, respectively. There is.

[Effect]

In the above-described high-frequency electro-hydraulic servo valve device of the present invention, when high-frequency alternating current is supplied to the electromagnetic drive mechanism, the valve shaft also performs high-frequency reciprocating motion, and the first spool valve and the first spool valve are integrally connected to the valve shaft. The two spool valves also perform reciprocating motion, but for example, considering the forward movement of each spool valve, after the working liquid supplied from the working liquid supply source through the working liquid supply channel is discharged from the first spool valve, After passing through the first flow path, the working fluid is supplied to one load section of the load member, and at this time, the working fluid in the other load section of the load member is supplied via the second oil path. It is adapted to be discharged from the second spool valve and then returned to the working fluid reservoir through the reservoir flow path.

Also, considering the forward movement of each spool valve, the working liquid supplied from the working liquid supply source through the working liquid supply channel is discharged from the second spool valve, and then passes through the second channel. , the working liquid in one of the load parts of the load member is discharged from the first spool valve via the first flow path, and is then supplied to the reservoir. The fluid is adapted to be returned to the working fluid reservoir through the flow path.

From then on, in response to the reciprocating movement of the valve shaft and thus the spool valve, the first spool valve applies hydraulic pressure to one loaded portion of the load member, and the hydraulic fluid does not act on one loaded portion of the load member. sometimes second
Since the spool valve can apply hydraulic pressure to the other load section of the load member, the hydraulic fluid can be alternately supplied and discharged to each load section of the load member, thereby allowing the load member to operate at high speed. It is possible.

〔Example〕

Hereinafter, a high-frequency electro-hydraulic servo valve device as an embodiment of the present invention will be explained with reference to the drawings. FIG. 2 is a longitudinal sectional view thereof. and a return port R, and a first
and second load-side ports C ₁ and C ₂ are provided.

The supply port P is connected to a hydraulic oil supply channel (working fluid supply channel) 3 from an oil pump 2 as a working fluid supply source, and the return port R is connected to a working fluid reservoir (hereinafter referred to as A reservoir flow path 5 leading to 4 (referred to as an "oil reservoir") is connected thereto.

Note that the oil pump 2 is connected to an oil reservoir 4.

Further, a first flow path 7 leading to a first oil chamber as one load part in the actuator 6 as a load member is connected to the first load side port _C1 , and a first flow path 7 leading to a first oil chamber as one load part in the actuator 6 as a load member is connected A second flow path 8 leading to a second oil chamber serving as the other load portion of the actuator 6 is connected to C ₂ .

The first and second oil chambers are partitioned by a piston fitted into the cylinder, and a rod is attached to the piston, and a test piece gripper is attached to the end of the rod. A chuck is provided.

Thereby, the present servo valve device V is interposed between the oil pump 2 and the oil reservoir 4, and the actuator 6 having two opposing oil chambers.

By the way, a pipe-shaped valve shaft 9 is fitted into the main body housing 1 so as to be reciprocatable in the axial direction.
The valve shaft 9 is driven by an electromagnetic drive mechanism (force motor) capable of generating high-frequency driving force in response to high-frequency alternating current, so that it can reciprocate.

That is, a drive coil member 12 to which a high-frequency alternating current is supplied is attached to one end of the valve shaft 9, and this drive coil member 12 is fitted into an annular gap 13a of a magnet 13 that generates a direct current magnetic field. As a result, the valve shaft 9 is reciprocated in the axial direction by an alternating electromagnetic force generated when the drive coil 12 receives high-frequency alternating current.

Furthermore, in accordance with the reciprocating movement of the valve shaft 9, the hydraulic oil supply channel 3 from the oil pump 2 communicates with the first channel 7 connected to one of the two load parts in the actuator 6, and the reservoir to the oil reservoir 4 is connected. Communication between the flow path 5 and the first flow path 7 is performed alternately 2
When the first spool valves 10a, 11a and the first spool valves 10a, 11a communicate the hydraulic oil supply channel 3 and the first channel 7 according to the reciprocating movement of the valve shaft 9, the reservoir flow Operates when the first spool valves 10a and 11a communicate the reservoir flow path 5 and the first flow path 7 by communicating the path 5 with the second flow path 8 connected to the other of the two load sections in the actuator 6. Two second spool valves 10b and 11b that communicate the oil supply channel 3 and the second channel 8 are respectively disposed on the valve shaft 9 at a predetermined interval.

With the above-described configuration, when high-frequency alternating current is supplied to the drive coil member 12, the valve shaft 9 also performs high-frequency reciprocating motion, and furthermore, the first spool valves 10a, 11a and the second spool valve 10 are integrally moved with the valve shaft 9.
b and 11b also perform reciprocating motion, but for example, when each spool valve moves to the right in Fig. 2 (during forward movement)
Considering this, the hydraulic oil as the hydraulic fluid that is branched from the oil pump 2 through the hydraulic oil supply channel 3 and the supply port P in the branch supply channel 14 is discharged from the first spool valves 10a and 11a, and then becomes the branched oil. 15 and the first load side port C ₁
The hydraulic oil in the second oil chamber of the actuator 6 is supplied to the first oil chamber of the actuator 6 after passing through the first flow path 7 and the second flow path 7. and second load side port
After passing through C ₁ and branching off at the branch oil path 16, it is discharged from the second spool valves 10b and 11b, and then merged at the branch return path 17, and then flowing through the return port R and the reservoir flow path 5 to the oil reservoir. It's starting to go back to 4.

Furthermore, considering the case where each spool valve moves to the left in FIG. is discharged from the second spool valves 10b and 11b, merges at the branch oil path 16, passes through the second load side port _C2 and the second flow path 8, and then enters the actuator 6.
At this time, the hydraulic oil in the first oil chamber of the actuator 6 is branched via the first flow path 7 and the first load side port _C1 . After being separated in the oil path 15, it is discharged from the first spool valves 10a and 11a, and then merged in the branch return path 17, and then returned to the oil reservoir 4 through the return port R and the reservoir flow path 5. There is.

From then on, the valve stem 9 and the spool valves 10a and 11
The first spool valves 10a, 11a are connected to the first spool valves 10a, 11a of the actuator 6 in accordance with the reciprocating movements of the
The second spool valves 10b and 11b apply hydraulic pressure to the second oil chamber of the actuator 6 when no hydraulic oil is acting on the first oil chamber of the actuator 6. Therefore, the hydraulic oil can be alternately supplied and discharged to each oil chamber of the actuator 6, thereby operating the actuator 6 at high speed and applying high-speed repetitive loads to the test piece held by its chuck. It is possible to add.

By the way, as the spool valve reciprocates, hydraulic oil is alternately supplied and discharged to each oil chamber of the actuator 6, and the amount of supply and discharge at this time is such that the displacement of the spool valve remains the same. In this case, compared to a conventional device having only one pair of spool valves, the number of spool valves in this embodiment is almost twice as large.

In this way, in the device of this embodiment, compared to conventional devices, the hydraulic oil flow rate can be increased without increasing the amount of displacement of each spool valve.
As described above, the actuator 6 can generate sufficient excitation force even in a high frequency range.

In addition, since the valve shaft 9 on which each spool valve is provided is formed into a pipe shape, the spool valve is
Even if a pair is provided, the weight does not increase significantly.

In addition, in FIG. 2, reference numerals 18 and 19 indicate neutral holding springs.

Furthermore, three or more first and second spool valves may be provided, and in this case, the amount of hydraulic oil supplied can be further increased.

〔Effect of the invention〕

As described in detail above, according to the high-frequency electro-hydraulic servo valve device of the present invention, the pipe-shaped valve shaft has a plurality of valve shafts that can alternately load a working fluid onto one of the two load portions of the load member. The simple structure includes one spool valve and a plurality of second spool valves that can alternately load the working fluid onto the other of the two load sections, and compared to conventional devices, there is no increase in weight or displacement of the spool valves. It is possible to alternately apply a high-speed and sufficient hydraulic pressure load to each load portion of the load member without causing an increase in the amount of pressure, and this has the advantage that the load member can be operated sufficiently even in a high frequency range. can get.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing a conventional electrohydraulic servo valve device, and FIG. 2 is a longitudinal sectional view showing an electrohydraulic servo valve device of the present invention. DESCRIPTION OF SYMBOLS 1... Body housing, 2... Oil pump as a working fluid supply source, 3... Hydraulic oil channel as a working fluid channel, 4... Oil reservoir as a working fluid reservoir, 5... Reservoir channel, 6...
Actuator as a load member, 7...first flow path, 8...second flow path, 9...valve shaft, 10a, 11
a...first spool valve, 10b, 11b...second
Spool valve, 12... Drive coil member, 13...
Magnet, 13a... Annular gap, 14... Branch supply path, 15, 16... Branch oil path, 17... Branch return path, 18, 19... Neutral holding spring,
C ₁ , C ₂ ... Load side port, P ... Supply port,
R...Return port, V...Servo valve device.

Claims (1)

[Claims] 1 a working liquid supply source and a working liquid reservoir;
In a servo valve device that is interposed between a load member having two load parts and can alternately apply hydraulic pressure to each load part of the load member, the servo valve device can generate high frequency driving force in response to high frequency alternating current. An electromagnetic drive mechanism and a pipe-shaped valve shaft that is reciprocated in the axial direction by the electromagnetic drive mechanism are provided, and a working liquid supply flow path from the working liquid supply source is provided according to the reciprocating movement of the valve shaft. a plurality of first spool valves that alternately communicate with a first flow path leading to one of the two load parts and a reservoir flow path to the working liquid reservoir and the first flow path; When the first spool valve communicates the working liquid supply channel and the first channel in accordance with the reciprocating motion of the shaft, a second spool valve is connected to the reservoir channel and the other of the two load sections. a plurality of second spool valves that communicate with the working liquid supply channel and the second channel when the first spool valve communicates the reservoir channel and the first channel; A high-frequency electro-hydraulic servo valve device, characterized in that spool valves are respectively arranged at predetermined intervals on the valve shaft.