JP5312269B2 - Hydraulic pump and compression test apparatus using hydraulic pump - Google Patents

Description

  The present invention relates to a hydraulic pump and a compression test apparatus using the hydraulic pump, and more particularly to a hydraulic pump that discharges hydraulic oil with a plunger and a compression test machine that uses the hydraulic pump.

  Conventionally, vane pumps and gear pumps have been used as hydraulic pump generators. This type of hydraulic pump has a feature that it is suitable for continuous discharge because it introduces hydraulic oil between adjacent vanes or adjacent teeth and moves the hydraulic oil to the discharge port while compressing the hydraulic oil. However, since hydraulic oil is pumped by rotation of a plurality of vanes and teeth, there is a problem that pulsation is likely to occur in the hydraulic oil and the hydraulic actuator that receives the supply of hydraulic oil is likely to be affected.

  On the other hand, there is also known an actuator (hydraulic pump) that accommodates a piston in a cylinder so as to be able to reciprocate and discharges hydraulic oil by the piston (Patent Document 1). However, since the hydraulic oil for operating the piston of the actuator is often supplied from a hydraulic pump such as the vane pump as described above, there is a problem that it is difficult to eliminate the influence of the pulse rate.

JP-A-2004-257448

  Thus, conventionally, it has been attempted to supply hydraulic oil using an actuator using a cylinder and a piston. However, since the piston is operated by hydraulic pressure, it is difficult to eliminate the influence of pulsation. . In addition, since the pressure acting on the piston is determined by the vane and the number of gears and the rotation speed of the vane and the gears, it is difficult to control the piston operating speed and the piston operating amount. There is a problem that it is difficult to control the oil discharge amount and the hydraulic oil pressure.

  For this reason, at the same time as the invention of the present application, the present applicant considered that the piston is pushed out by a manual feed screw in a hydraulic pump composed of a cylinder and a biston, but it is difficult to manually adjust the rotation speed of the feed screw. There is a problem that it is difficult to adjust the discharge amount of hydraulic fluid and the pressure of hydraulic fluid. In addition, in order to shorten the length of the feed screw and make the device compact, it is necessary to make the handle for rotating and feeding the feed screw follow the movement of the piston, and the configuration is complicated. There was a problem of becoming.

  The present invention uses a hydraulic pump capable of finely adjusting the pressure and discharge amount of hydraulic oil and allowing the plunger to be pushed in by a fixed motor in a hydraulic pump including a cylinder and a plunger. An object is to provide a compression test apparatus.

  In order to solve the above-described problems, the present invention provides a motor, a drive sprocket attached to and rotated by an output shaft of the motor, a joint rotatably supported by a fixed system and parallel to the motor, A driven sprocket that is integrally attached to the joint and transmits a rotational driving force thereto; an endless chain that is wound around the driven sprocket and the driving sprocket and transmits the rotational driving force from the driving sprocket to the driven sprocket; A feed screw connected to the joint so as not to rotate and to be movable in the axial direction, and a support portion fixed to the front of the feed screw in the screw feed direction and screwing the feed screw forward and backward. A plunger that is disposed forward of the feed screw in the feed direction and is moved forward by the feed screw in the screw feed direction, and insertion of the plunger A cylinder that pressurizes the hydraulic oil more, a discharge unit that discharges the hydraulic oil pressurized by the insertion of the plunger from the cylinder, and a resilient force that is always retracted toward the plunger to urge the plunger. There is provided a hydraulic pump provided with a return spring that always makes a rear end surface abut against a front end surface of the feed screw directly or via a rotary seat.

  Further, the present invention provides a fixed table, a movable table arranged opposite to the fixed table, and the movable table disposed between the movable table and the fixed table by moving the movable table to the fixed table side. A cylinder portion that compresses the compressed sample, and a pressure measurement portion that measures the hydraulic pressure of the cylinder portion, and the movable table is fitted to the cylinder portion so as to be movable by a predetermined stroke, and the cylinder The hydraulic pressure introduction of compressing the compressed sample by connecting the discharge part of the hydraulic pump according to claim 1 and operating the movable table in the compression direction of the compressed sample via a piston accommodated in the cylinder chamber. A compression test apparatus using a hydraulic pump provided with a port is provided.

  According to the present invention, in a hydraulic pump including a cylinder and a plunger, the plunger is pushed into the cylinder by a fixed motor, so that fine adjustment of the hydraulic oil pressure and fine adjustment of the discharge amount are possible. Further, the apparatus can be made compact. Further, in the compression test apparatus using such a hydraulic pump, since the fine adjustment of the hydraulic oil pressure and the fine adjustment of the discharge amount can be performed, a highly accurate and reliable compression test can be performed.

FIG. 1 is a cross-sectional view showing a hydraulic pump according to an embodiment of the present invention. FIG. 2 is a detailed cross-sectional view of the main part of FIG. 1 showing the joint according to the embodiment of the present invention. FIG. 3 is a cross-sectional view taken along line AA in FIG. FIG. 4 is a block diagram showing a concrete compression test apparatus. FIG. 5 is an enlarged cross-sectional view showing a hydraulic part of the compression pump and the concrete compression test apparatus according to the embodiment of the present invention.

  An embodiment of a hydraulic pump according to an embodiment of the present invention and a compression testing machine that performs a compression test of a compressed sample using the hydraulic pump will be described below with reference to the accompanying drawings.

  First, a hydraulic pump according to an embodiment of the present invention will be described with reference to FIGS. 1 and 3. 1 is a cross-sectional view showing a hydraulic pump, FIG. 2 is a detailed cross-sectional view of an essential part of FIG. 1 showing a joint, and FIG. 3 is a cross-sectional view taken along line AA of FIG. FIG. 5 is an enlarged sectional view showing a hydraulic part of the compression pump and the concrete compression test apparatus according to the embodiment of the present invention.

  As shown in FIG. 1, the hydraulic pump 1 is attached to a base plate 3 supported at a predetermined height by a plurality of legs 2. The hydraulic pump 1 includes a cylinder block 6 having a cylinder 4 and a plunger 5. The cylinder 4 opens to one side and the other side of the base plate 3, and the opening 7 on one side is closed by a plug 8 having a taper screw.

  An end plate 10 is attached to the other opening 9 of the cylinder block 6 with bolts. The cylinder block 6 is provided with a discharge port 11 as a discharge portion for discharging hydraulic oil. The discharge port 11 is directly connected via the relay port 12 of the base plate 3 facing the cylinder of the hydraulic operating device such as a compression tester or the hydraulic operating device such as a compression tester described later via the hydraulic pipe 13. Connected to other cylinders. The connection portion of the discharge port 11 with the relay port 12 is expanded in the radial direction for sealing, and a seal ring 15 is attached.

  The end plate 10 is provided with a guide hole 16 as a guide portion for guiding the plunger 5 to the cylinder 4. The guide hole 16 is provided concentrically with the cylinder 4 and guides the plunger 5 in a slidable manner and supports the plunger 5 so as not to tilt. The seal is provided on the joint surface between the end plate 10 and the cylinder block 6 and the contact surface between the guide hole 16 and the plunger 5. In the present embodiment, a seal ring 17 is provided concentrically with the guide hole 16 on the joint surface of the end plate 10 to the cylinder block 6, and a seal ring concentric with the guide hole 16 is provided on the inner surface of the guide hole 16 that contacts the plunger 5. 18 is provided. When the seal rings 17 and 18 are provided, leakage of hydraulic oil from the cylinder 4 is prevented, so that reliability is improved.

  Next, a device that pulls the plunger 5 back from the cylinder to the initial position and a device that pushes the plunger 5 into the cylinder will be sequentially described.

  First, a device for pulling back the plunger 5 from the cylinder 4 will be described. As the pull-back device, a device that is separated from the pushing device and functions independently is preferable. In the present embodiment, a return spring 20 is used. The return spring 20 is disposed between the back surface of the end plate 10 and the rear end portion of the plunger 5. In the present embodiment, the return spring 20 is inserted into the outer peripheral surface of the plunger 5. A spring retainer 19 is provided at the rear end of the plunger 5, and a spring retainer 19 b is also provided on the back surface of the end plate 10.

  When the return spring 20 is inserted into the plunger 5 and inserted into the guide hole 16, and the plunger 5 is pushed into the cylinder 4 with the return spring 20 seated on the spring retainers 19 and 19b, the return spring 20 contracts due to the pushing force. The elastic force is accumulated with the contraction. When the pushing force against the plunger 5 is released, the plunger 5 returns to the original no-load position (hereinafter referred to as the initial position) by the elastic force accumulated by the return spring 20.

  As described above, when the return spring 20 is used as the pull-back device, a complicated mechanism becomes unnecessary and maintenance is facilitated. Further, it is not necessary to incorporate a device for pulling back the plunger 5 with respect to the device for pushing the plunger 5, and the device can be configured simply, so that the cost can be reduced.

Next, a pushing device for pushing the plunger 5 into the cylinder 4 will be described.
As described above, since the plunger 5 is automatically pulled back by the return spring 20, the pushing device pushes the plunger 5 into the cylinder 4 when discharging the hydraulic oil, and otherwise the initial position of the return spring 20 It suffices if it has a function of retreating.

  As a device that can realize such a function, a hydraulic actuator can be used, but it is not preferable because another device including a hydraulic pump is required. Moreover, if a feed screw is used, the hydraulic pressure can be adjusted precisely and continuously, but the function cannot be utilized manually. Therefore, the pushing device includes a feed screw 21, a joint 22 for rotating the feed screw 21, a motor 23 for rotating the joint 22, and a control device for controlling the motor.

  In the present embodiment, the feed screw 21 is screwed into the screw hole 25 formed in the support portion 24 fixed between the one side portion and the other side portion of the base plate 3. The screw hole 25 is provided concentrically with the guide hole 16 of the cylinder 4 and the end plate 10. Thereby, the plunger 5 can be smoothly pushed along the guide hole 16, and the pushing force of the feed screw 21 can be smoothly transmitted to the plunger 5. Further, abnormal wear and galling of the plunger 5 and the guide hole 16 can be suppressed, and the maintenance cycle can be extended.

  Further, a rotating seat 26 is attached to the distal end portion of the feed screw 21 between the distal end surface of the feed screw 21 and the back surface of the spring retainer 19 in order to prevent the plunger 5 and the return spring 20 from rotating due to frictional force. As shown in FIG. 2, the rotary seat 26 is formed in a cup shape, and is supported by a stepped portion provided at the tip of the feed screw 21 via bearings 27 and 28. When the rotary seat 26 is supported by the bearings 27 and 28 as described above, the rotary seat 26 can be rotated even with a small frictional force. As shown in FIG. 2, a thrust bearing is used for one of the bearings 27 and 28, and a radial bearing is used for the other.

  A joint 22 for transmitting the rotational driving force of the motor 23 to the feed screw 21 is provided below the base plate 3 in parallel with the output shaft 29 of the motor 23. As shown in an enlarged view in FIG. 2, the joint 22 includes bearings 35, 35 on the support portion 24 of the base plate 3 and a support portion 34 attached to the lower surface of the base plate 3 so as to be separated from the support portion 24. Supported through. A drive sprocket 30 is attached to the output shaft 29 of the motor 23, and a driven sprocket 31 is attached to the input portion of the joint 22. An endless chain 33 is wound around the drive sprocket 30 and the driven sprocket 31 through an opening 32 below the output shaft 29 provided on the base plate 3. Accordingly, the motor 23 can rotate, stop, and switch the rotation direction of the joint 22.

Next, a connection structure between the feed screw 21 and the joint 22 will be described with reference to FIGS.
The joint 22 is provided with an insertion hole 36 for inserting a feed screw into the shaft core portion, and coupling portions 38 and 38 are provided in the body portion of the joint 22 with the insertion hole 36 interposed therebetween. The connecting portions 38, 38 are formed of openings that open to both the outer side and the insertion hole 36, and are each formed in a long hole shape extending from one end portion of the joint 22 to the other end portion along the axial direction of the joint 22. Is done.

  Most of the feed screw 21 is accommodated in the joint 22 at the initial position of the return spring 20. The rear end portion of the feed screw 21 is provided with a pin insertion hole 37 that penetrates the rear end portion of the feed screw 21 along the radial direction. When the coupling portions 38, 38 are caused to face the pin insertion hole 37 by the rotation of the joint 22, the pin 41 can be passed from the one coupling portion 38 to the pin insertion hole 37 of the feed screw 21 and inserted into the other coupling portion 38. it can. When the pin 41 is inserted, the feed screw 21 is connected to the joint 22 by the pin 41.

  In this state, the feed screw 21 and the joint 22 are not rotatable relative to each other. In addition, the pin 41 can move along the connecting portions 38 and 38. In this case, in order to improve the movement of the pin 41, it is preferable to dispose a guide member having good slidability in the connecting portions 38 and 38 and to support the pin 41 on the connecting portions 38 and 38 via the guide member. .

  In the present embodiment, guide members 39 and 39 are provided in the connecting portions 38 and 38, respectively. The guide members 39, 39 are formed in a rectangular shape that can be slid along the connecting portion 38, and are provided with pin insertion holes 40 for inserting the pins 41. The length of the pin 41 is such that the pin 41 passes through the pin insertion holes 37 and 40 with the guide members 39 and 39 sandwiching the rear end portion of the feed screw 21, and a snap ring 42 such as a C ring on the outside thereof. It is determined so that a mounting groove 43 for mounting can be provided. When the snap ring 42 is attached to a position outside the guide members 39, 39, the guide members 39, 39 and the pin 41 can be prevented from being detached, and the connection of the feed screw 21 to the joint 22 can be maintained.

Next, the operation of the hydraulic pump according to this embodiment will be described with reference to FIGS.
When the motor 23 is driven, the output shaft 29 of the motor 23 rotates, the drive sprocket 30 rotates integrally with the output shaft 29, and the driven sprocket 31 rotates via the endless chain 33. The joint 22 rotates integrally with the driven sprocket 31, and the feed screw 21 rotates integrally with the joint 22 via the pin 41 and the guide member 39. At this time, the guide member 39 provided at the rear end portion of the feed screw 21 moves in the screw advance direction along the connecting portions 38 and 38.

  When the output shaft 29 of the motor 23 is rotated in the insertion direction of the plunger 5, the feed screw 21 presses the plunger 5 via the rotary seat 26. When the plunger 5 is inserted deeply into the cylinder 4, the return spring 20 contracts greatly, and the return spring 20 accumulates the elastic force. At this time, when a frictional force is generated between the rotary seat 26 and the back surface of the spring retainer 19, the rotary seat 26 rotates. Thereby, the twist of the return spring 20 and the accompanying rotation of the plunger 5 are prevented, and the occurrence of uneven wear in the plunger 5 and the guide hole 16 of the end plate 10 can be prevented.

  The rotational speed of the motor 23 is determined based on the specifications of the hydraulic actuator, and is controlled by a control unit (controller) described later. For example, the discharge speed is obtained from the pressure of the pressure detection unit that detects the pressure of the discharge port 11 and the change rate of the pressure, and the rotation speed of the motor 23 is adjusted. When the discharge of hydraulic oil to the hydraulic actuator is finished, the motor 23 is stopped by a stop button, and then the motor 23 is reversely rotated by a reverse button (return button) of the motor 23. When the motor 23 is reversed, the joint 22 is reversed and the feed screw 21 is reversed. The plunger 5 returns to the initial position by the elastic force accumulated by the return spring 20. At this time, when the pressure detection unit detects a pressure corresponding to the initial position of the plunger 5, the control unit stops supplying power to the motor 23. As a result, the plunger 5 is stopped at the initial position.

The hydraulic pump 1 according to the present embodiment can be modified as follows.
(1) Change in pitch of feed screw By changing the pitch of the feed screw 21, the discharge amount per unit time can be adjusted for each hydraulic actuator. For example, if the rotation speed of the motor 23 is constant and the pitch of the feed screw 21 is reduced, the insertion speed of the plunger 5 into the cylinder 4 can be reduced, and the discharge amount of hydraulic oil per unit time discharged from the discharge port 11 Can be reduced. Thereby, the fine adjustment of the pressure with respect to a hydraulic actuator becomes possible. Further, since the hydraulic oil can be continuously supplied, the reliability is high. When changing the pitch of the feed screw, the feed screw 21 and the support portion 24 are exchanged.

(2) Change of lead of lead screw When the pitch of the lead screw 21 and the rotation speed of the motor 23 are made constant and the diameter of the lead screw 21 is changed, the advance amount and the thrust per one turn of the lead screw 21 can be changed. . For example, if the rotation speed of the motor 23 is constant and the lead is made small (the diameter of the feed screw is made small), the insertion speed of the plunger 5 into the cylinder 4 can be made small, and the unit of hydraulic oil discharged from the discharge port 11 The discharge amount per time can be reduced. This facilitates fine adjustment of the pressure on the hydraulic actuator side. When changing the lead of the feed screw 21, the rotary seat 26, its bearings 27 and 28, the feed screw 21, and the support portion 24 are replaced.

(3) Change of plunger diameter When the pitch of the lead screw 21, the lead, the rotational speed of the motor 23, and the degree of insertion of the plunger 5 into the cylinder 4 are made constant, and the plunger 5 diameter is changed, the discharge amount of the hydraulic oil is changed. be able to. For example, when the diameter of the plunger 5 is reduced, the volume of the plunger 5 at the same insertion depth is reduced, so that the discharge amount of hydraulic oil can be reduced accordingly. This facilitates fine adjustment of the pressure on the hydraulic actuator side. When changing the diameter of the plunger 5, the diameter of the cylinder 4 is increased in advance, and the end plate 10, the return spring 20, the spring retainer 19, and the plunger 5 are replaced.

(4) Combination of (1) to (3) When combining (1) to (3), various changes are possible. In this case, the corresponding part is replaced.

The hydraulic pump according to this embodiment has the following effects.
(1) Since it is not necessary to move the motor and the joint in response to the advance and retreat of the plunger with respect to the cylinder, the structure of the device can be simplified and made compact.
(2) The discharge amount and discharge speed of hydraulic oil can be changed by changing each part.
(3) Since a motor is used, highly reliable hydraulic control can be performed.
(4) Since the disassembly and assembly can be performed easily, maintenance is easy.
(5) Since the hydraulic device and the control device are mounted on the base plate and the port of the hydraulic device can be connected to the discharge port of the cylinder through the relay port of the base plate, the hydraulic piping can be simplified.
(6) Since the hydraulic oil can be supplied to the hydraulic actuator in a state where there is no pulsation, fluctuations in pressure can be suppressed. Thereby, the reliability is greatly improved.

  Next, an embodiment of a concrete compression test apparatus using the hydraulic pump 1 will be described with reference to FIGS. 4 and 5. The concrete compression test apparatus is a test machine that applies a predetermined compression load to a concrete sample cut into a columnar shape and measures the resistance of the concrete.

  FIG. 4 is a configuration diagram of a concrete compression test apparatus according to the present embodiment. The concrete compression test apparatus 45 is mounted on the hydraulic pump 1 described above, specifically, on the base plate 3. The compression test device 45 is provided so as to face the movable table 48, a cylinder portion 46 fixed to the base plate 3, a movable table 48 fitted to the cylinder portion 46 so as to be movable in the axial direction. A fixed table 49 and a pair of posts 50 and 50 for arranging the fixed table 49 at a predetermined interval from the movable table 48 are provided.

  The compression test device 45 is provided with a pressure detector (not shown) that detects the hydraulic pressure of the cylinder 46 and a control panel 51 that controls the operation of the hydraulic pump 1. The posts 50, 50 are screwed with bolts such as cap screws into a plurality of screw holes (not shown) provided in one side surface and the other side surface of the cylinder portion 46 and the fixed table 49 that are arranged opposite to each other. Are linked by In the present embodiment, the post 50 is formed of a side plate having a predetermined thickness and is reinforced by a rib as necessary. However, the post 50 may be formed using another member, for example, a pipe material having a predetermined thickness. If the post 50 is coupled to the cylinder portion 46 and the fixed table 49 and configured as a portal as a whole, the mutual strength can be increased.

  As shown in FIG. 5, the cylinder portion 46 is divided into a lower pedestal 52 and an upper cylinder member 53, and they are integrated by fitting together. In the present embodiment, the cylinder member 53 is fixed to the pedestal 52 by the cylinder presser 67 that is seated on the upper surface of the pedestal 52. That is, a columnar protrusion 55 that fits the cylinder member 53 is integrally provided on the upper surface of the pedestal 52. A groove 56 is provided on the outer peripheral surface of the projecting portion 55 so as to seal between the inner peripheral surface of the cylinder member 53 and a seal ring 57 is attached.

  A flange 54 for fixing the cylinder member 53 to the pedestal 52 is provided along the circumferential direction on the outer peripheral portion of the cylinder member 53. The flange 54 is provided at the bottom of the cylinder member 53 and is seated on the pedestal 52. The cylinder retainer 67 includes a fitting portion 63 that fits on the outer peripheral surface of the cylinder member 53, a seating portion 64 that sits on the flange portion 54 of the cylinder member 53, and a cylinder that sits on the peripheral portion of the protruding portion 55 of the pedestal 52. A portion 65 is provided. The cylindrical portion 65 of the cylinder retainer 67 is fitted to the outer peripheral surface of the flange portion 54 of the cylinder member 53 with a predetermined clearance.

  The fitting part 63 of the cylinder holder 67 is fitted to the outer peripheral surface of the cylinder member 53, the seating part 64 of the cylinder holder 67 is seated on the flange part 54 of the cylinder member 53, and the cylindrical part 65 of the cylinder holder 67 is When the cylinder holder 67 is fastened to the pedestal 52 with a bolt such as a cap screw while being seated on the peripheral edge of the protruding portion 55, the cylinder portion 46 can be integrated with the pedestal 52. In this way, the divided structure facilitates manufacture. In addition, since disassembly is possible, maintenance becomes easy.

  As a configuration for the movable table 48, a hydraulic oil reservoir 58 is provided on the upper surface of the protruding portion 55, and a piston 81 for operating the movable table 48 is accommodated on the hydraulic oil reservoir 58. In this embodiment, in order to transmit the hydraulic oil pressure evenly to the piston 81, the hydraulic oil reservoir 58 has the axial center of the protruding portion 55 as the apex, and the intersection with the outer peripheral edge of the protruding portion 55 as the bottom. It is formed in an inverted conical shape. Further, a groove 82 is provided on the outer peripheral surface of the piston 81 so as to smoothly slide and seal, and a seal ring 83 is fitted therein.

  The protruding portion 55 and the pedestal 52 are provided with a hydraulic oil introduction port 60. The hydraulic oil introduction port 60 opens to the apex portion of the hydraulic oil reservoir 59 and the bottom surface of the pedestal 52, and is connected to the discharge port 11 of the hydraulic pump 1 through the relay port 12. The opening on the bottom surface of the pedestal 52 of the hydraulic oil introduction port 60 is a diameter-expanded portion 61 that is expanded radially outward for sealing, and a seal ring 62 such as an O-ring is attached. When the seal ring 62 is attached to the enlarged diameter portion 61, it is possible to prevent the hydraulic oil from leaking out at the peripheral portion of the hydraulic oil introduction port 60 on the upper surface of the base plate 3.

  As a result, the hydraulic oil discharged from the discharge port 11 of the hydraulic pump 1 is supplied to the hydraulic oil reservoir 58 through the relay port 12 and the piston 81 is moved to the fixed table side by the pressure of the hydraulic oil reservoir. Can be moved.

  A set of swing tables 75 and 76 having a concave spherical surface and a protruding spherical surface are attached to the fixed table 49 on the surface facing the movable table 48. The swing table 75 having a projecting spherical surface is integrally attached to the fixed table 49, and the other swing table 76 is a concrete table (compressed sample) 80 placed on the movable table 48, and then the concrete. The sample is placed on the upper surface of the sample, and is engaged with the convex spherical surface of one swinging table 75 by moving the movable table 48 toward the fixed table. The pair of swing tables 75 and 76 swings according to the inclination of the concrete sample, but the concrete sample 80 is centered on the movable table 48 as the pair of swing tables 75 and 76 swings. Therefore, a highly reliable compression test can be performed.

  As shown in FIG. 4, the control panel 77 of the compression test apparatus 45 is mounted on the other side of the base plate 3 and houses the motor 23 on the base plate 3. In addition, on the bottom side of the control panel 77, a partition plate that partitions the motor 23 from the electrical wiring is provided in the control panel 77.

  In the control panel 77, a power button 78 that enables operation by turning on the power supply circuit that controls the motor 23, and the plunger 5 is inserted into the cylinder 4 of the hydraulic pump 1 by rotating the motor 23 in the forward rotation direction. As a result, the hydraulic oil is discharged into the hydraulic oil reservoir 58 of the compression test device 45 to raise the piston 81 of the cylinder 47, and as a result, the compression button 84 for raising the movable table 48 and the motor 23 are stopped, and the plunger 5 A stop button 85 for stopping the operation and a return button 86 for returning the plunger 5 by reversing the motor 23 are provided.

  Further, by adjusting the rotational drive of the motor 23, the compression speed dial 87 for setting the compression speed for the concrete sample, that is, the pressurization speed, and the light when the compression load for the concrete sample reaches the set pressure are respectively turned on. There are provided a plurality of pressure monitoring lamps 88 and 89, and an abnormality monitoring lamp 90 which is turned on when an abnormal pressure is detected.

  The control unit has a digital input unit 91 and a digital display unit 92, and is configured to set a set value of pressure and a set value of abnormal pressure for a concrete sample by a button provided on the digital display unit 92. Has been. On the other hand, the control unit compares the preset pressure with the pressure of the hydraulic oil reservoir 58 or the hydraulic oil introduction port 60 detected by the pressure detection unit, and the comparison result reaches the set value of the pressure monitoring lamps 88 and 89. When this occurs, the corresponding pressure monitoring lamp is turned on, and when the comparison result is abnormal pressure, the abnormality monitoring lamp 90 is turned on.

  In this way, the compression test device 45 can set the pressure by operating the button or dial, and can visually check the end of the compression and the abnormal state with the lamp, greatly improving the operability and reliability as a testing machine. can do. Further, since the pressure setting accuracy is high using the hydraulic pump 1 and the compression test (including the destructive test) of the concrete sample can be performed in a state where the pressure fluctuation is extremely small, highly reliable data can be obtained. .

DESCRIPTION OF SYMBOLS 1 Hydraulic pump 2 Leg part 3 Base plate 4 Cylinder 5 Plunger 6 Cylinder block 7 Opening part 8 Plug 9 Opening part 10 End plate 11 Discharge port 12 Relay port 13 Hydraulic piping 15 Seal ring 16 Guide hole 17 Seal ring 18 Seal ring 19 Spring Retainer 19b Spring retainer 20 Return spring 22 Joint 23 Motor 24 Support part 25 Hole 26 Rotating seat 27 Bearing 29 Output shaft 30 Drive sprocket 31 Driven sprocket 32 Opening 33 Endless chain 34 Support part 35 Bearing 36 Insertion hole 37 Pin insertion hole 38 Connection Part 39 Guide member 40 Pin insertion hole 41 Pin 42 Snap ring 43 Groove 45 Compression test device 46 Cylinder part 47 Cylinder 48 Movable table 49 Fixed table 50 Post 51 Control Panel 52 Pedestal 53 Cylinder Member 54 Gutter 55 Projecting Portion 56 Groove 57 Seal Ring 58 Hydraulic Oil Reservoir 59 Hydraulic Oil Reservoir 60 Hydraulic Oil Introducing Port 61 Expanded Portion 62 Seal Ring 63 Fitting Portion 64 Seating Portion 65 Cylindrical Portion 70 Relay port 71 Hook 75 Swing table 76 Swing table 77 Control panel 78 Power button 80 Concrete sample (compressed sample)
81 Piston 82 Groove 83 Seal ring 84 Compression button 85 Stop button 86 Button 87 Pressure speed dial 88 Pressure monitoring lamp 90 Abnormality monitoring lamp 91 Digital input section 92 Digital display section

Claims (2)

  A motor, a drive sprocket attached to and rotated by the output shaft of the motor, a joint rotatably supported by the fixed system and supported in parallel with the motor, and a joint integrally attached to the joint; A driven sprocket that transmits rotational driving force, an endless chain that is wound around the driven sprocket and the driving sprocket and transmits rotational driving force from the driving sprocket to the driven sprocket, and is non-rotatable with respect to the joint and axially A feed screw that is movably connected, a support portion that is fixed in front of the feed screw in the screw feed direction, and that has a screw hole that allows the feed screw to be advanced and retracted, and is arranged in front of the feed screw in the feed direction. A plunger that is moved forward in the screw feed direction by the feed screw, and a cylinder that pressurizes hydraulic oil by inserting the plunger, A discharge portion that discharges hydraulic oil pressurized by insertion of the plunger from the cylinder, and a rear end surface of the plunger that is constantly energized in a backward direction with respect to the plunger, and a front end surface of the feed screw And a return spring that is always brought into contact directly or via a rotary seat.   A compressed table arranged between the movable table and the fixed table is compressed by moving the fixed table, a movable table arranged opposite to the fixed table, and moving the movable table to the fixed table side. And a pressure measuring unit that measures the hydraulic pressure of the cylinder unit, and the movable table is fitted to the cylinder unit so as to be movable by a predetermined stroke. A hydraulic pressure introduction port for compressing the compressed sample by connecting the discharge part of the hydraulic pump described above and operating the movable table in the compression direction of the compressed sample via a piston housed in the cylinder chamber is provided. A compression test apparatus using the hydraulic pump according to Item 1.

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