JP2002013482A - Stroke length indicating mechanism of reciprocating machine having variable stroke mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stroke length indicating mechanism having a simple structure and enabling the easy reading of stroke length. SOLUTION: A control capacity pump 1 adjusts stroke length by moving a crank shaft 16 to change in eccentric amount, and reciprocates a movable member at the adjusted stroke length. In the control capacity pump 1, a lead screw 26 moving the crank shaft with screwed with a crank case side internally having a variable stroke mechanism is provided. The lead screw 26 is connected with a connecting shaft 28 having variable positional interrelationship in an axial direction and integrally rotating with the lead screw, and provided with a mechanical counter 40 indicating a numeric value according to rotations of the connecting shaft.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stroke length display mechanism for a reciprocating machine such as a control displacement pump capable of adjusting a discharge amount by adjusting a stroke length of a plunger.

[0002]

2. Description of the Related Art There are a vernier type and a dial type as a stroke length indicating mechanism in a conventional reciprocating machine, for example, a control displacement pump.

The vernier type stroke length display mechanism is provided with a scale on the outer periphery of an operation handle (or cap) that rotates when adjusting the stroke length so that the rotational position of the operation handle can be read, and a case near the operation handle. A scale for reading the advance / retreat of the operation handle is provided, a higher numerical value is read by a scale on the case side, and a lower numerical value is read by a scale on the operation handle side.

On the other hand, a dial-type stroke length display mechanism is embedded in the operation handle in a state where the same attitude is maintained independently of rotation of the operation handle, that is, in a state where it is urged by the weight. In this configuration, the rotation of the operation handle is input by decelerating with a worm gear, the pointer is rotated based on the decelerated rotation, and the numerical value of the scale indicated by the pointer is read.

[0005]

However, in the conventional vernier type stroke length display mechanism, the operation handle moves up and down, that is, moves forward and backward when adjusting the stroke length. Since it is difficult to read, it is easy to make a reading error. In addition, since the scale is exposed to the outside, the scale becomes thin after a long period of time, and the reading becomes more difficult. Furthermore, since it is extremely difficult to seal the lubricating oil of the crank mechanism, the motor cannot be mounted vertically, which requires a large installation space.

Further, since the dial type stroke length display mechanism uses a worm gear, it is troublesome to manufacture and cannot be provided at a low cost. In addition, since it is embedded inside the operation handle, it is essential to provide a weight for preventing the operation handle and co-rotation, and the structure becomes complicated. Then, even when biased by the weight, if the operation handle is rotated, the scale will oscillate like a pendulum, making it difficult to read.

The present invention has been proposed in view of the above circumstances, and an object of the present invention is to provide a stroke length display mechanism having a simple structure and capable of easily reading a stroke length.

[0008]

SUMMARY OF THE INVENTION The present invention has been proposed to achieve the above-mentioned object, and according to the first aspect of the present invention, the eccentric amount is changed by moving an eccentric amount adjusting member so that the stroke is changed. In a reciprocating machine having a variable stroke mechanism for adjusting the length and reciprocating the movable member with the adjusted stroke length, a lead for screwing with the case side containing the variable stroke mechanism to move the eccentric amount adjusting member A screw is provided, and the lead screw has a variable positional relationship in the axial direction, a connecting shaft that rotates integrally with the lead screw is connected, and a counter that displays a numerical value according to the rotation of the connecting shaft is provided. The stroke length is adjusted by moving the eccentric amount adjusting member via the connecting shaft and the lead screw by the rotation of the stroke adjusting external input member provided on the connecting shaft. A stroke length display mechanism, characterized by being configured to display an adjustment stroke length on the display unit of the counter by the rotation of the interlocking shaft.

According to a second aspect of the present invention, an input shaft of a mechanical counter is connected to the connecting shaft via a rotation transmitting mechanism, and the eccentricity is provided via the connecting shaft and the lead screw by rotation of an external input member for stroke adjustment. The stroke length is adjusted by moving an amount adjusting member, and the input shaft is rotated by rotation of the connecting shaft to display the adjusted stroke length on a display unit of a counter. 2 is a stroke length display mechanism.

According to a third aspect of the present invention, the counter is arranged on a disk member provided with a detected portion and rotatably disposed, and on a movement locus of the detected portion accompanying rotation of the disk member. An electronic counter comprising: a detector capable of detecting the detected part, a calculation unit to which a detection signal from the detector is input, and a display unit for displaying a numerical value based on a display control signal from the calculation unit The stroke length is adjusted by moving the eccentric amount adjusting member via the connecting shaft and the lead screw by the rotation of the stroke adjusting external input member, and the disk member is rotated by the rotation of the connecting shaft to detect the stroke. The calculation unit is configured to calculate an adjustment stroke length based on a detection signal output from the detector in accordance with the detection of the unit, and the calculated adjustment stroke length is displayed on a display unit. It is the stroke length indication mechanism of claim 1, wherein the.

According to a fourth aspect of the present invention, there is provided the stroke length display mechanism according to the third aspect, wherein a supporting shaft which rotates together with the disk member is connected to the connecting shaft via a rotation transmitting mechanism.

According to a fifth aspect of the present invention, the rotation transmission mechanism is constituted by a gear, and a gear provided on the connecting shaft and the connecting shaft are integrally formed. It is a display mechanism.

According to a sixth aspect of the present invention, a nut is fixed to one end of the lead screw, and a hollow portion having a cross-sectional shape into which the nut can be fitted is formed in the connecting shaft in the axial direction. The stroke length display mechanism according to any one of claims 1 to 5, wherein the rotation of (i) is transmitted to the lead screw via a nut to move the lead screw in the axial direction.

According to a seventh aspect of the present invention, the counter includes a zero-return operation unit for resetting the display to zero, and at least the zero-return operation unit is covered with a cover, and the zero-point return operation unit is externally operated during operation. The stroke length display mechanism according to any one of claims 1 to 6, wherein the operation cannot be performed.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. The reciprocating machine shown in the drawing is a control displacement pump 1 used in a chemical plant (for example, a pilot plant) or the like. By providing a motor 2 in a vertical direction, the installation space can be saved and a stroke length adjusting unit is provided. 3, the stroke length display section 4 provided in the stroke length adjusting section 3 makes the display easier to read. It should be noted that the control displacement pump 1 can be installed with the motor 2 placed sideways, and the installation direction can be appropriately selected according to the installation space.

The control displacement pump 1 is, as shown in FIG.
A crank mechanism unit 5 for converting the rotational motion of the motor 2 into reciprocating motion; a pump cylinder unit for reciprocating a plunger 6 as a movable member by the reciprocating motion converted by the crank mechanism unit 5 to pump the liquid; And a stroke length adjusting unit 3 for adjusting a stroke length when converting the rotary motion into the reciprocating motion in the unit 5. FIG. 1 is a schematic configuration perspective view of the control displacement pump 1 as viewed from below, in which a part of a pump cylinder portion (cylinder or the like) which is attached to an output shaft of a motor 2 downward and protrudes laterally is omitted. A plunger 6 as a movable member or a rod of a piston is connected to a connecting rod 10 via a plunger adapter 7 and a crosshead 8 and a crosshead pin 9.

The crank mechanism 5 has a motor 2 mounted downward on a top surface of a crankcase 11 which is a case in the present embodiment, and a worm shaft 13 connected to an output shaft of the motor 2 via a coupling 12. 11, both ends are supported vertically by bearings 14, 14, and a crank mechanism is provided in a direction orthogonal to the worm shaft 13.

As shown in FIG. 3, the crank mechanism has an X-shaped crankshaft 16 (an eccentricity according to the present invention) which is formed with slanted ridges 15 on both sides of the shaft so as to be movable in the axial direction. X-shaped crankshaft 16).
A circular plate-shaped cam 17 having an oblique groove 18 on the inner surface of the notch through-opening 19 and a crankshaft 16 which can be penetrated concentrically. A notch hollow shaft (hollow shaft) 24 having a notch portion 23 which forms a hollow portion 22 and is fitted in the notch through opening 19 so that the cam 17 can be moved in the radial direction but is prevented from moving in the axial direction. And a connecting rod 10 in which a cam 17 is rotatably fitted to a large end hole at one end and a crosshead pin 9 attached to the crosshead 8 is fitted to a small end hole at the other end.

In this crank mechanism, the X-shaped crankshaft 1
When the shaft 6 is moved in the axial direction, the cam 17 is moved in the direction (radial direction) perpendicular to the axial direction by the obliquely inclined ridges 15 to change the amount of eccentricity. That is, the distance from the center line of the hollow shaft 24 to the center line of the cam 17 changes in a state where the cam 17 is fitted into the cutout portion 23 of the hollow shaft 24 and the two rotate integrally. Since the helical gear portion of the worm shaft 13 is meshed with the worm wheel 20 attached by a key on the same axis as the hollow shaft 24, the hollow shaft 24 can be rotated by the rotating force of the motor 2, When the cam 24 and the crankshaft 16 rotate integrally, the crosshead 8 and the plunger 6 can reciprocate via the connecting rod 10 according to the amount of eccentricity of the rotating cam 17.

The stroke length adjusting section 3 includes a crankshaft 16
Is connected to the end of the crankshaft 16 via an idle coupling 25.
6, one end of the lead screw 26 is screwed into a female screw formed in the crankcase 11 and a nut 27 is fixed to the other end of the lead screw 26 protruding from the crankcase 11. And nut 2
An operation handle 29 as an external input member for stroke adjustment is attached to an end portion of a connecting shaft 28 connected via the connecting member 7 to form a schematic configuration. The idle coupling 25 is
It is a joint that connects the crankshaft 16 and the lead screw 26 in a state where the moving force in the axial direction is transmitted but the rotational force is not transmitted. Therefore, the crankshaft 16 and the lead screw 26 move integrally in the axial direction, but are independent of each other in rotation. In the present embodiment, the female screw portion screwed to the male screw portion of the lead screw 26 is formed on the crankcase 11, but this female screw portion is a portion that does not move with respect to the crankshaft 16, specifically, the crankcase 11 The first case may be any.

The connecting shaft 28 is a plastic hollow shaft integrally formed with a gear 30 near the end on the operation handle 29 side, and has a hollow portion 3 on an end surface opposite to the operation handle 29.
1 is open. The hollow portion 31 is formed in a shape that restricts the rotation of the nut 27 so that the fitted nut 27 can move in the axial direction and rotates integrally with the nut 27. In the present embodiment, as shown in FIG. 4, since the nut 27 is hexagonal, the hollow portion 31 is formed in a hexagonal cross-sectional shape corresponding to this.

Therefore, when the operating shaft 29 is rotated by operating the operation handle 29, the lead screw 26 can be rotated via the nut 27, and the rotation causes the lead screw 26 to be screwed into the female screw portion of the crankcase 11. If necessary, move in the axial direction. That is, the connecting shaft 28
Is a shaft whose axial relative position with respect to the lead screw 26 is variable and which rotates integrally with the lead screw 26. Even if the operation handle 29 is rotated to move the lead screw 26, the hollow portion 31 of the connecting shaft 28 and the nut 27 absorb the movement of the lead screw 26, so that the operation handle 29 does not move in the axial direction. Absent.

The connecting shaft 28 and the lead screw 26
The connection structure may be any configuration as long as the mutual positional relationship in the axial direction is variable and the lead screw 26 is integrally rotated, and may be, for example, a quadrangle, a spline configuration, and a pin. A fitting long hole may be used.

As described above, the idle coupling 25 is a joint that connects the two shafts while the transmission of the rotational force between the crankshaft 16 and the connecting shaft 28 is cut off. Transmission, and transmits only the moving force in the axial direction. Therefore, even when the crankshaft 16 rotates, the lead screw 26 can be prevented from rotating together. When the lead screw 26 is moved in the axial direction, the X-type crankshaft 16
And move in the axial direction. When the crankshaft 16 moves in the axial direction, the fitting position between the inclined ridge 15 of the crankshaft 16 and the cam 17 changes, whereby the cam 17 moves to adjust the amount of eccentricity, that is, the stroke length. be able to. After the stroke length is adjusted, the lock screw 33 is tightened and the tip is pressed against the side surface of the lead screw 26, whereby the rotation of the lead screw 26 is stopped and locked.

When the groove 18 of the cam 17 is fitted in the center of the inclined ridge 15, the center line of the cam 17 and the crankshaft 16
The plunger 6 does not reciprocate even when the crankshaft 16 is rotated, but when the crankshaft 16 is moved in the axial direction from this state, the groove 18 The center line of the cam 17 deviates from the center line of the crankshaft 16 and is eccentric. The length twice as large as the eccentric amount is the stroke length, and the state where the groove 18 is fitted to the end of the inclined ridge 15 is the maximum stroke length.

Next, the stroke length display section 4 will be described. In this embodiment, as shown in FIGS. 2 and 5, a mechanical counter 40 is provided with its input shaft 41 arranged in parallel with the connecting shaft 28, and the input shaft 4 of the counter 40 is provided.
1 and the connecting shaft 28 are connected by gears 30, 34, 42. The mechanical counter 40 has “0” to “9” on the outer peripheral surface.
Since the four drums 43 are provided with the numbers up to the number, the four-digit number can be displayed by a four-digit number. When the input shaft 41 rotates and the lowermost drum 43 makes one rotation, the upper drum 43 becomes 36 A number obtained by incrementing by one degree (1/10 rotation) and displaying +1 is displayed, and by repeating this, the number of each digit is visually displayed on the display unit. As shown in FIG. The drum 43 is covered with a display window plate 45 attached to the opening of the display device, and numerals are displayed through the display window plate 45. Therefore, it is possible to prevent the numbers on the drum 43 from fading or disappearing even after a long period of time.

In the present embodiment, since the gears 30, 34, and 42 are connected to the connecting shaft 28, the reduction ratio of these gears 30, 34, and 42 is appropriately set, so that the stroke is reduced. The length can be displayed as a percentage between a minimum and a maximum, such as in percent, or the actual stroke length can be displayed, for example, in millimeters. In the drawing, three gears 30, 3
4, 42, the rotation direction of the operation handle 29 and the rotation direction of the numbers on the drum 43 can be made to match with each other in relation to the screw of the lead screw 26, and a natural feeling is obtained when the operation handle 29 is operated. Can be operated with.
The number of gear stages can be appropriately selected. Also, the axial direction of the input shaft 41 can be appropriately changed by using, for example, a bevel gear.

As described above, when the stroke length is displayed as a numerical value by the mechanical counter 40, misreading can be reduced. Further, in the present embodiment, since the connecting shaft 28 only rotates and does not move in the axial direction, the seal for sealing the lubricating oil of the crank mechanism is easier than the conventional vernier type. Specifically, as shown in FIG. 5, by providing seal members 47, 47 such as O-rings at the end of the connecting shaft 28, it is possible to reliably prevent the lubricating oil from leaking to the counter side. Therefore, the motor 2 can be mounted in the vertical direction, the counter 40 can be mounted on the stroke adjusting section 3 projecting in the horizontal direction, and the display window 45 can be mounted upward, so that it is easy for the operator to see. Further, since the mechanical counter 40 has a simple structure, it is hard to break down, has excellent durability, and is inexpensive.

Further, in an assembling operation or an assembling operation in an assembling factory, a zero point adjusting operation for matching the actual stroke length with the display of the counter 40 is required.
In the present embodiment, the display window plate 45 attached to the cover 44 is removed, and the stroke length adjusting unit 3 is operated while the connecting shaft 28 and the counter 40 are connected to set the actual stroke length to zero. , Display window plate 45
Of the counter 40 (reset button) 46 is operated from the opening on the back side of the counter. By this operation, the numerical value of the drum 43 displayed on the counter 40 is simultaneously set to “0”.
It can be. Therefore, the zero point adjusting operation can be performed extremely easily without performing a troublesome operation of disconnecting the connection between the connecting shaft 28 and the counter 40, such as removing the counter 40. Then, when the zero-point adjusting operation is completed, the display window plate 45 is attached to the opening of the cover 44 to cover the zero-return operation unit 46 so that the operation of the zero-return operation unit 46 cannot be performed from the outside.

In this embodiment, since characters and symbols such as "%" and "mm" are written on the inner surface of the display window plate 45, these symbols fade or disappear even after a long period of time. Never do.

Although the mechanical counter for inputting the rotation of the connecting shaft 28 is used as the counter 40 in the above embodiment, an electronic counter may be used instead of the mechanical counter 40. Hereinafter, another embodiment configured as described above will be described.

As shown in FIG. 7, the counter 50 according to the present embodiment is an electronic counter including a disk member 51, a detector 52, a calculation unit 53, and a display unit 54.

The disk member 51 and the detector 52 constitute a so-called rotary encoder. That is, the disk member 51 is a light-shielding disk-shaped member provided with a slit (light-transmitting portion) as a kind of a detected portion at a peripheral portion, and at the center thereof, like the input shaft 41 of the mechanical counter 40. The thus configured support shaft 55 is attached so as to penetrate in the plate thickness direction, and rotates together with the support shaft 55 around the support shaft 55. On the other hand, the detector 52 is a photo-interrupter capable of detecting a slit, and is arranged on a locus of movement of the slit accompanying rotation of the disk member 51 so as to detect the slit. Accordingly, when the disk member 51 rotates together with the support shaft 55, the slit is caused by the rotation of the disk member 51 to cause the detector 5 to rotate.
2 and a pulse-like detection signal is output from the detector 52 with the passage of the slit. And the support shaft 55
Is connected to the connecting shaft 28 via gears 30, 34, 42, which are a kind of rotation transmitting mechanism, as in the above-described embodiment, and thus rotates with the rotation of the connecting shaft 28.

When the disk member 51 is provided on the support shaft 55 as in this embodiment, the diameter of the disk member 51 can be reduced, which contributes to downsizing of the counter 50. In the present embodiment, the rotation of the connecting shaft 28 is increased by setting the reduction ratio of the gears 30, 34, 42 to increase the speed of the support shaft 55.
To tell. That is, the rotation amount of the support shaft 55 is
Is larger than the amount of rotation. Thus, the rotation amount of the disk member 51 can be increased, and the resolution of the encoder can be increased. Further, regarding the disk member 51 and the detector 52, any configuration may be used as long as a detection signal is output from the detector 52 in accordance with the rotation of the disk member 51. For example, the detector 52 may be configured by a magnetic sensor. A magnet (corresponding to a kind of a detected part) is provided on the disk member 51 as a magnetic source, and a magnetic sensor is arranged on the locus of movement of the magnet to determine the strength of a magnetic field that changes as the disk member 51 rotates. May be used for detection. In addition, the detector 52 is constituted by a micro switch, and a protrusion (corresponding to a kind of a detected portion) is formed on the disk member 51, and the micro switch is arranged on the movement locus of the protrusion to rotate the disk member 51. Thus, the microswitch and the protrusion may be brought into contact with each other to output a detection signal from the microswitch.

The arithmetic unit 53 is constituted by a so-called one-chip microcomputer having a CPU,
2. It is electrically connected to the zero return operation unit 56 (reset switch) and the display unit 54. This operation unit 53
Calculates the adjustment stroke length based on the detection signal from the detector 52, outputs a display control signal for displaying the calculation result to the display unit 54, and adjusts the adjustment stroke length by the reset signal from the zero return operation unit 56. Reset length to "0". The display unit 54 includes an electrical display element capable of displaying numbers, for example, a 7-segment display or a liquid crystal display, and displays the adjustment stroke length based on a display control signal from the calculation unit 53. In the present embodiment, the display unit 54 is formed by a panel-like member incorporating an electric display element.
It is attached to the cover 44 so as to close the opening of the cover 44 from the outside and to be detachable from the cover 44 or to be opened and closed with respect to the cover 44 by a hinge mechanism or the like. That is, the display unit 54 also functions as a lid member that closes or opens the opening of the cover 44, and disables the zero return operation unit 56 from the outside when the opening is closed.

As for the display section 54, any display element can be adopted as long as the adjustment stroke length can be displayed. However, a 7-segment LED, a dot matrix type LED, and a liquid crystal display with a backlight can be used. And a light-emitting display element such as a plasma display. This is because the adjustment stroke length can be easily read even when working in a dark place.

Also in this embodiment, when the operating handle 29 of the stroke length adjusting section 3 is rotated, the connecting shaft 28 is rotated, the lead screw 26 and the X-shaped crankshaft 16 are moved in the axial direction, and the cam 17 is moved. Because it is eccentric,
The stroke length can be adjusted. At this time, in the electronic counter 50, the rotation of the operation handle 29 rotates the gear 30, and the rotation of the gear 30 is transmitted to the support shaft 55 by the gears 34 and 42, and the rotation of the support shaft 55 causes the disk member 51 to rotate. It rotates, and the detector 52 outputs a detection signal. Based on the detection signal from the detector 52, the arithmetic unit 5
Numeral 3 calculates the stroke length and outputs a display control signal corresponding to the calculation result to the display unit 54, and the display unit 54 receiving the display control signal displays the calculated stroke length. Therefore, also in the present embodiment, even if the stroke length is adjusted, the operation handle 29 and the display unit 54 do not move in the axial direction of the lead screw 26, and the stroke length can be easily read. Further, since the display unit 54 displays the stroke length as a number, misreading can be reduced, and a large-sized electric display element can be used, so that the stroke length can be easily visually recognized even from a distant place. be able to.

The actual stroke length and the display unit 54
In the present embodiment, with respect to the zero adjustment operation for adjusting the display of the display, the panel-shaped display unit 54 attached to the cover 44 is detached or the like, and the zero return operation unit 5 is opened from the opening of the cover 44.
6 is exposed and the actual stroke length is reduced to zero by operating the stroke length adjusting unit 3 while the connecting shaft 28 and the support shaft 55 are connected. In this state, the zero return operation unit 56 is operated to display the display unit 54. Is set to "0". Therefore, the zero point adjustment operation can be performed extremely easily. When the zero adjustment operation is completed, the display unit 54 is attached to the opening of the cover 44 so that the operation of the zero return operation unit 56 cannot be performed from the outside.

In the electronic counter 50, the stroke length is displayed on the display unit 54. Since the stroke length is the result of the calculation by the calculation unit 53, the data of the stroke length is transmitted to the outside of the control displacement pump 1. You can also output. In this case, an external output terminal is electrically connected to the arithmetic unit 53, and an electric wiring such as a connector is connected to the external output terminal. When the stroke length data is configured to be externally output as described above, it is advantageous for remote control of the control displacement pump 1 and the usability can be improved. It is also convenient for automating the operation record of the control displacement pump 1.

The above embodiment is an example of the present invention, and the design can be changed as appropriate within the scope described in the claims. For example, the external input member for stroke adjustment is not limited to the operation handle 29,
A coupling connected to the output shaft of a servomotor (not shown) may be used. In this case, the connecting shaft 28 can be rotated by driving the servo motor, so that remote control is possible. Also, the lead screw 26 and the connecting shaft 2
The rotation transmitting mechanism for connecting the gear 8 with the gear 8 is not limited to the gears 30 and 42, but may be a sprocket and a chain, a stepped pulley and a stepped belt, or the like.

In the above embodiment using the electronic counter 50, the connecting shaft 28 and the supporting shaft 5 are connected via the rotation transmitting mechanism.
5 is provided on the support shaft 55 side by connecting it to the support shaft 55, but is not limited to this configuration, and may be provided directly on the connecting shaft 28. For example, the disk member 51 may be protruded from the peripheral surface of the connecting shaft 28 in a radial direction orthogonal to the axial direction. Further, the display unit 54 is configured by a dot matrix display capable of displaying in dots such as a liquid crystal display or an LED display, and the stroke length is displayed in a plurality of forms of figures such as numerical values and bar graphs. You may comprise.

The reciprocating machine of the present invention is not limited to the control displacement pump 1, but has a variable stroke mechanism for adjusting the stroke length by changing the eccentric amount by moving the eccentric amount adjusting member. However, any configuration may be used as long as it is a machine that reciprocates the movable member with the adjusted stroke length. For example, a reciprocating compressor may be used. The eccentric amount adjusting member is not limited to the X-shaped crankshaft 16 having the inclined ridge portion 15, but may be a combination of a conventional N-shaped crankshaft having a slanted crankshaft and an eccentric cam.

[0043]

According to the present invention as described above, the following effects can be obtained. According to the first aspect of the present invention, a lead screw is provided for moving the eccentric amount adjusting member by screwing with the case side containing the variable stroke mechanism, and the mutual positional relationship in the axial direction of the lead screw is variable. A connecting shaft that rotates integrally with the lead screw is connected, a counter that displays a numerical value according to the rotation of the connecting shaft is provided, and the connecting shaft and the lead are rotated by the rotation of a stroke adjusting external input member provided on the connecting shaft. The stroke length is adjusted by moving the eccentric amount adjustment member via the screw, and the adjustment stroke length is displayed on the display unit of the counter by the rotation of the connecting shaft. Therefore, even if the stroke length is adjusted, an external input for stroke adjustment is performed. Since the member does not move in the axial direction, the stroke length can be easily read. Therefore, misreading can be reduced. Also, since the configuration is simple,
Easy to manufacture and maintain.

According to the second aspect of the present invention, since the counter is a mechanical type, the structure is simple and the transmission ratio of the rotation transmission mechanism is high.
The rotation direction and the display direction can be easily changed. Therefore, even if the reciprocating portion is redesigned, it is only necessary to change the transmission ratio, and the design change of the stroke length display mechanism can be simplified.

According to the third aspect of the present invention, the counter is provided on the disk member provided with the detected portion and rotatably disposed, and on the movement locus of the detected portion accompanying the rotation of the disk member. Since it is an electronic type including a detector capable of detecting the detected portion, a calculation unit to which a detection signal from the detector is input, and a display unit that performs numerical display based on a display control signal from the calculation unit, The stroke length can be extracted by an electric signal. Therefore, the degree of freedom in displaying the stroke length is high, and it is possible to easily cope with automation of control and operation management.

According to the fourth aspect of the present invention, since the supporting shaft that rotates together with the disk member is connected to the connecting shaft via the rotation transmitting mechanism, the disk member can be provided in a small size, and the display mechanism can be downsized. Can be planned.

According to the fifth aspect of the present invention, the rotation transmitting mechanism is constituted by a gear, and the gear provided on the connecting shaft and the connecting shaft are integrally formed, so that the number of parts can be reduced and the structure can be further simplified. Can be promoted and supplied at low cost. In addition, the degree of freedom of the direction of the counter can be increased, so that the counter can be arranged at a position easy to see.

According to the sixth aspect of the present invention, a nut is fixed to one end of the lead screw, and a hollow portion having a cross-sectional shape into which the nut can be fitted is formed in the connecting shaft in the axial direction. The rotation of the lead screw is transmitted to the lead screw via the nut, so that the lead screw is moved in the axial direction. The nut can absorb the movement of the lead screw. Therefore, since the operation handle does not move in the axial direction, the operation is easy, and the servo unit can be easily added to the lead screw.

According to the seventh aspect of the present invention, the counter includes a zero return operation unit for returning the display to zero, and the zero return operation unit is covered with a cover, and the zero return operation unit is operated from outside the cover. Since the operation is disabled, it is possible to prevent the zero return operation unit from being operated in the normal state. And, since the counter is provided with a zero return operation unit, assembly work in an assembly factory,
Alternatively, in the maintenance work, in the work of matching the actual stroke length and the display of the display mechanism, the actual stroke length is set to zero while the connecting shaft and the counter are connected, and the display window plate is removed in this state, and so on. The numerical value of the counter can be set to “0” simply by operating the reset operation unit of the counter. Therefore, when adjusting the display of "0" of the counter, the adjustment operation can be performed extremely easily without removing the counter and cutting off the connection between the connecting shaft and the counter each time. Then, when this adjustment work is completed, it is possible to prevent the operation of the zero return operation unit from being performed by attaching a display window plate or the like, so that the display is effectively prevented from being distorted during operation. be able to.

When the counter is constituted by a mechanical counter, and this counter is also covered with a cover together with the zero return operation section, the characters on the counter can be prevented from disappearing or fading even after a long period of time. When a part of the cover is formed by the display window plate of the counter, characters and symbols can be written on the inner surface of the display window plate, and such a problem that the characters and symbols disappear or fade away. It can also be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic configuration perspective view of a control displacement pump, which is an embodiment of a reciprocating machine, viewed from below.

FIG. 2 is a sectional view of a variable stroke mechanism and a stroke length display mechanism.

FIG. 3 is a perspective view of a main part of the variable stroke mechanism.

4A is a plan view of a nut, and FIG. 4B is a side view of the nut.

FIG. 5 is a sectional view of a stroke length display mechanism using a mechanical counter.

FIG. 6 is a front view of a stroke length display mechanism using a mechanical counter.

7A is a cross-sectional view of a stroke length display mechanism using an electronic counter, and FIG. 7B is a block diagram illustrating an electrical configuration of a stroke length display mechanism using an electronic counter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Control displacement pump 2 Motor 3 Stroke adjustment part 4 Stroke length display part 5 Crank mechanism part 6 Plunger 7 Plunger adapter 8 Crosshead 9 Crosshead pin 10 Connecting rod 11 Crankcase 12 Coupling 13 Warm shaft 14 Bearing 15 Slope projection 16 Crankshaft 17 Cam 18 Groove 19 Notch through opening 20 Worm wheel 22 Hollow portion 23 Notch portion 24 Notch hollow shaft (hollow shaft) 25 Idle coupling 26 Lead screw 27 Nut 28 Linking shaft 29 Operating handle 30, 34, 42 Gear 31 Hollow part 32 Bearing 33 Lock screw 40 Mechanical counter 41 Input shaft 43 Drum 44 Cover 45 Display window plate 46, 56 Zero return operation part 47 Sealing material 50 Electronic counter 51 Disc member 52 detector 53 calculating unit 54 display unit 55 pivot

Claims (7)

[Claims] 1. A reciprocating machine that has a variable stroke mechanism that adjusts a stroke length by changing an eccentric amount by moving an eccentric amount adjusting member, and that reciprocates a movable member with the adjusted stroke length. A lead screw is provided for moving the eccentricity adjusting member by screwing with the case side containing the stroke mechanism, and the lead screw has a variable mutual positional relationship in the axial direction and rotates integrally with the lead screw. A counter for displaying a numerical value according to the rotation of the connecting shaft is provided, and the eccentricity adjusting member is moved via the connecting shaft and the lead screw by the rotation of the stroke adjusting external input member provided on the connecting shaft. To adjust the stroke length and display the adjusted stroke length on the display of the counter by the rotation of the connecting shaft. Stroke length display mechanism according to claim. 2. An input shaft of a mechanical counter is connected to the connecting shaft via a rotation transmitting mechanism, and an eccentric amount adjusting member is moved via the connecting shaft and the lead screw by rotation of a stroke adjusting external input member. The stroke length display mechanism according to claim 1, wherein the stroke length is adjusted, and the input shaft is rotated by the rotation of the connecting shaft to display the adjusted stroke length on a display unit of a counter. . 3. The device according to claim 1, wherein the counter is disposed on a disk member provided with a detected portion and rotatably disposed, and on the movement locus of the detected portion with the rotation of the disk member to detect the detected portion. An electronic counter including a possible detector, a calculation unit to which a detection signal from the detector is input, and a display unit for displaying a numerical value based on a display control signal from the calculation unit; The stroke length is adjusted by moving the eccentric amount adjusting member via the connecting shaft and the lead screw by the rotation of the external input member, and the disk member is rotated by the rotation of the connecting shaft, and the detection is performed in accordance with the detection of the detected portion. The arithmetic unit calculates an adjustment stroke length based on the detection signal output from the display unit, and the calculated adjustment stroke length is displayed on a display unit. Stroke length display mechanism according to 1. 4. The stroke length display mechanism according to claim 3, wherein a support shaft that rotates together with the disk member is connected to the connection shaft via a rotation transmission mechanism. 5. The stroke length display mechanism according to claim 2, wherein the rotation transmission mechanism is constituted by a gear, and a gear provided on the connection shaft and the connection shaft are integrally formed. 6. A nut is fixed to one end of the lead screw, a hollow portion having a cross-sectional shape in which the nut can be fitted is formed in the connecting shaft in the axial direction, and rotation of the connecting shaft is
The stroke length display mechanism according to any one of claims 1 to 5, wherein the lead screw is transmitted to the lead screw via a nut to move the lead screw in the axial direction. 7. The counter according to claim 1, further comprising a zero-return operation unit for returning the display to zero, wherein at least the zero-return operation unit is covered by a cover so that the zero-point return operation unit cannot be operated from outside during operation. The stroke length display mechanism according to any one of claims 1 to 6, wherein: