JP2001115951A - Delivery pump adjustment mechanism - Google Patents

Abstract

(57) [Problem] To provide a delivery adjusting mechanism of a delivery pump capable of efficiently and accurately controlling the amount of the delivered liquid and the like regardless of the amount of the delivered liquid. SOLUTION: A cylinder (24) having a suction port (24a) and a discharge port (25b) formed therein, and a piston forming a pump cavity (23a) and sliding in the cylinder (24) are provided. ), The liquid is sucked into the pump cavity (23a) from the suction port (24a) by the combined operation of the rotational movement and the reciprocating movement, and the delivery amount of the delivery pump (2) discharging this liquid from the discharge port (24b). An adjusting mechanism, comprising: a stroke changeable mechanism that can change the stroke of the reciprocating motion; and a stroke determining mechanism that determines the stroke.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a delivery amount adjusting mechanism of a pump for delivering a liquid by a combined operation of a rotational movement and a reciprocating movement of a piston sliding in a cylinder.

[0002]

2. Description of the Related Art Various types of pump mechanisms for delivering liquid are already known, such as a gear pump and a vane pump. A gear pump is a pump that rotates gears that mesh with each other in a sealed casing and sends out liquid by this rotation. The vane pump is a pump that forms a space by a cam ring and a vane attached to a rotor, and sends out a liquid by changing the volume of the space. When a liquid is delivered using each of these pumps, the amount of the liquid delivered per unit time is controlled by controlling the rotation speed of a gear or a rotor. Therefore, when the rotation speed is secured to a certain level or more, a desired liquid can be sent out.

[0003]

However, in each of the above pumps, when the amount of liquid to be sent out in one cycle is small,
That is, when it is necessary to keep the rotation speed below a certain level, the flow of the liquid is not performed smoothly, and it has been difficult to accurately control the amount of the liquid to be sent out. Therefore,
An object of the present invention is to provide a delivery adjusting mechanism of a delivery pump that can efficiently and accurately control the amount of the delivered liquid and the like regardless of the amount of the delivered liquid.

[0004]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a cylinder having a suction port and a discharge port formed at corresponding positions in a circumferential direction, and a pump cavity formed on a circumferential wall, and the inside of the cylinder is formed. A sliding mechanism for rotating the piston about an axis; and a reciprocating mechanism for reciprocating the piston in the axial direction. A delivery amount adjusting mechanism of a delivery pump that sucks a liquid into the pump cavity and discharges the liquid from the discharge port, wherein the stroke changeable mechanism enables a change in the stroke of the reciprocation; And a stroke determining mechanism for determining the delivery amount of the delivery pump.
ADVANTAGE OF THE INVENTION According to this invention, the sending amount of liquid can be adjusted by changing the stroke of reciprocation.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION
This will be specifically described with reference to the drawings as appropriate. FIG. 1 is a schematic side view showing the entire structure of a coating apparatus including a delivery pump according to the first embodiment. The delivery pump 2 according to the present embodiment is provided in a coating apparatus 1 for performing color change coating of an automobile body. First, a brief description will be given of the color change painting of the automobile body. In the painting of the car body, on top of the undercoat, which is rustproof paint by electrodeposition coating,
Apply a middle coat, and apply a top coat of the specified color on top of the middle coat.

[0006] In a coating line for an automobile body, a paint is spouted from a coating apparatus to the automobile body sequentially conveyed by a conveyor, and a predetermined coating is applied. In this case, the amount of the paint and the timing at which the paint is ejected need to correspond to the transport speed of the car body being transported.
In other words, in order to secure the coating accuracy, it is necessary to control the amount of the paint to be delivered and the timing of the delivery as accurately as possible. Here, according to the delivery pump 2 according to the present embodiment, it is easy to adjust the delivery amount and the delivery timing of the paint, and the delivery control is easy.

The coating apparatus 1 shown in FIG. 1 mainly includes a delivery pump 2, a paint tank 3, an in-side flow path 4 connecting the paint tank 3 and the delivery pump 2, and a pressure inside the in-side flow path 4 being kept constant. A preload pump 5 for smoothly feeding the paint to the delivery pump 2, a servomotor 6 for rotatingly driving a rotary drum 21 of the delivery pump 2, an inclined cylinder 7 for determining the inclination of the delivery pump 2, and a paint spray from the delivery pump 2. An out-side flow path 9 connecting to the outlet 8 is provided.

The rotary drum 21 of the delivery pump 2 is supported on the base 11 in a rotatable state. A rod 22 is connected to the rotating drum 21, and a piston 23 is connected to a lower end of the rod 22. The piston 23 slides in the cylinder 24. A rectangular swing plate 72 is attached to the base 11, and the advance / retreat rod 71 of the tilt cylinder 7 and the cylinder 24 are connected via the swing plate 72. Therefore, when the retractable rod 71 expands and contracts, the swinging plate 7
2 tilts, and further the cylinder 24 tilts.

The rotary drum 21 of the delivery pump 2 is connected to the servo motor 6 via a flexible wire 61.
That is, by controlling the drive of the servomotor 6, the rotation of the rotary drum 21 is controlled. When the rotating drum 21 rotates, the piston 23 in the cylinder 24 performs a combined operation of a rotational motion and a reciprocating motion. A suction port 24a and a discharge port 24b are formed at two opposing positions on the peripheral wall of the cylinder 24 according to the present embodiment.

The "corresponding position in the circumferential direction" described in claim 1 is not limited to only the opposed position as in the present embodiment. That is, when the inside of the cylinder 24 is viewed from the rotating drum 21, the suction port 24 a and the discharge port 24
This includes a case where b is symmetrical with respect to the center line of the cylinder 24 (the rotation axis of the piston 23). Therefore, the suction port 24a and the discharge port 24b may be shifted vertically (in the direction of the center line of the cylinder 24). The suction port 24a is connected to the in-side flow path 4, and the pressurizing pump 5 and the paint tank 3 are connected to the in-side flow path 4. The discharge port 24b is connected to the out-side flow path 9, and the paint outlet 8 is formed at the tip of the out-side flow path 9.

The general operation of the coating apparatus 1 will be described.
First, the drive speed of the rotary drum 21 is adjusted by controlling the drive of the servomotor 6. In addition, the drive control of the tilt cylinder 7 controls the amount of expansion and contraction of the advance / retreat rod 71 to adjust the tilt angle of the cylinder 24. Incidentally, in the present embodiment, the inclination angle of the cylinder 24 is HI and L
Switching can be performed in two stages of OW, and adjustment is performed by this switching.

The rotation speed of the piston 23 in the delivery pump 2 and the stroke of the piston 23 are adjusted by adjusting the rotation speed of the rotary drum 21 and the tilt angle of the cylinder 24. By adjusting the rotation speed of the piston 23, the timing at which the paint is sent out, that is, the timing from the time when the paint is ejected to the time when the paint is ejected next, is adjusted. On the other hand, by adjusting the stroke of the piston 23, the amount of paint to be sent out is adjusted. A mechanism for adjusting the stroke of the piston 23 corresponds to a “delivery amount adjusting mechanism”.

In the delivery pump 2 according to the present embodiment, the rotation speed and the stroke of the piston 23 can be independently adjusted. Therefore, for example, there are the following advantages. If the stroke is set to be relatively long, if the amount of paint sprayed out per unit time is adjusted only by adjusting the rotational speed of the piston 23, pulsation may occur due to the need to take a long time.
On the other hand, if the stroke is set to be relatively short, it may be necessary to adjust the rotation speed of the piston 23 to an extremely high speed.
In some cases, it cannot be inhaled. Here, as in the present embodiment, if a “delivery amount adjusting mechanism” is provided, it is possible to select an optimal feeding state from both sides of the adjustment of the rotation speed and the adjustment of the stroke, which is preferable.

The delivery amount adjusting mechanism of the delivery pump 2 according to the present embodiment will be described in further detail. FIG. 2 is a cross-sectional view of the delivery pump, and (1) to (4) show each step of the delivery pump that sends out paint. In addition,
(A) in each of FIGS. (1) to (4) is a longitudinal sectional view, and (b) is Y
It is -Y sectional drawing. A suction port 24a and a discharge port 24b are formed at opposing positions on the peripheral wall of the cylinder 24, and a piston 23 slides in the cylinder 24. The piston 23 has a part cut off from the cylinder to form a pump cavity 23a on the peripheral wall. The pump cavity 23a according to the present embodiment has a shape in which a part of the arc of the outer circumference is partially cut away from the lower end upward along the axis.

FIG. 2 (2) shows a state in which the piston 23 has reached the highest position (hereinafter referred to as top dead center). FIG. 2 (4) shows a state in which the piston 23 has been lowered most. The position (hereinafter, referred to as a bottom dead center) is shown. At the positions of the top dead center and the bottom dead center, the suction port 24a
And the discharge port 24b must be closed by the peripheral wall of the piston 23. At other positions, the pump cavity 23a needs to be able to communicate with either the suction port 24a or the discharge port 24b.

That is, the shape and the like of the pump cavity 23a are such that the suction port 24a and the discharge port 24b can be closed when the piston 23 reaches the upper and lower dead points, and at other positions, the suction port 24a or the discharge port 2a can be closed.
4b. Therefore, the shape and the like of the pump cavity 23a are relatively derived from the positions where the suction port 24a and the discharge port 24b are formed, or the stroke of the piston 23 that is appropriately changed.

The lower end of the rod 22 is fixed to the upper end of the piston 23. The upper part of the rod 22 is bent at a right angle, and the tip is connected to the inner peripheral surface of the rotating drum 21.
The rotating drum 21 is a cylindrical body that covers the ceiling 21a,
The tip of the rod 22 is connected to the inner peripheral surface via a spherical bearing 21b. A flexible wire 61 is connected to the ceiling 21 a of the rotating drum 21. In addition, the rotating drum 21
It is rotatably supported on a base 11 (see FIG. 1).

When the rotating drum 21 rotates, the rod 22
Rotates, and the piston 23 also rotates. When the cylinder 24 is inclined with respect to the rotating drum 21, the rod 2
Since the bent portion 2 moves up and down, the piston 23 in the cylinder 24 reciprocates with this up and down movement. This reciprocation,
The paint is sucked and discharged into the cylinder 24 by the combined operation of the rotation and the rotation. The piston 23
And the intersection of the rotation axis of the rotating drum 21
Even if the inclination angle of the cylinder 24 is changed, the swing width is extremely small. Therefore, the intersection is defined as a fixed point, and an axis CL passing through the intersection and serving as a reference for the inclination angle of the cylinder 24 is defined as an inclination reference line.

The cylinder 24 containing the piston 23 is
As shown in FIG. 1, the tilt cylinder 7 is
The inclination angle is determined according to the amount of expansion and contraction of the advance / retreat rod 71. The relationship between the cylinder 24, the swing plate 72, and the reciprocating rod 71 will be described with reference to FIGS. By the way, FIG.
FIG. 2 is a view in the direction of the arrow X in FIG. 1. FIG. 4 is a view taken in the direction of the arrow Z in FIG. 3, that is, a view of the delivery pump viewed from the back of FIG.

The upper end of the swing plate 72 is supported by a horizontal pin 12 of the base 11. The axis of the horizontal pin 12 coincides with the inclination reference line CL. The cylinder 24 is fixedly mounted on one side surface of the swing plate 72 via a connecting member 73. On the other hand, the swing plate 7
A tilt cylinder 71 is connected to the other side surface of 2. This connection will be described in detail with reference to FIG. In addition,
As described above, FIG. 4 is a view taken in the direction of the arrow Z in FIG. 3 and partially broken.

At the lower portion of the rectangular swing plate 72, two parallel rail members 74, 7 are arranged along the longitudinal direction.
4 are provided. An engagement piece 75 is slidably engaged with the rail members 74, 74. A connecting pin 76 is rotatably attached to the engaging piece 75, and a fixing member 77 is attached to the connecting pin 76 (see FIG. 3).
The reciprocating rod 71 is connected via the. That is, when the reciprocating rod 71 expands and contracts, the swinging plate 72 smoothly tilts and moves with the rotation of the connecting pin 76 and the sliding movement of the engagement piece 75. The cylinder 24 is further fixed to the swing plate 72. Therefore, when the reciprocating rod 71 is protruded by an appropriate length, the inclination angle of the cylinder 24 with respect to the rotating drum 21 is determined as a result.

Next, the delivery of the paint by the delivery pump 2 will be described with reference to FIG. 2 (1) and (3) show the reciprocating movement of the piston 23, and FIG.
In (1), the piston 23 is in the process of sucking paint,
In FIG. 2C, the piston 23 is in the process of discharging the paint. 2 (2) and 2 (4) show a state where the piston 23 has reached the top dead center and the bottom dead center, as described above. In the process shown in FIG. 2A, FIG.
, The piston 23 is in the process of ascending. Also, in this process, as shown in FIG.
Is communicated with the suction port 24 a, and paint is sucked into the cylinder 24.

From the process shown in FIG.
When the rotation of No. 1 advances, the process moves to the process shown in FIG.
In this process, the piston 23 is at the top dead center and the rise of the piston 23 is momentarily stopped as shown in FIG. In this case, as shown in FIG. 2B, the pump cavity 23a is provided with the suction port 24a and the discharge port 2a.
4b. That is, the suction port 2
4a and the discharge port 24b are closed by the peripheral wall of the piston 23, and the paint that has entered the cylinder 24 once stops flowing.

The process shown in FIG.
When the rotation of No. 1 advances, the process proceeds to the process shown in FIG.
In this process, the piston 23 is in a descending process as shown in FIG. In this process, the pump cavity 23a communicates with the discharge port 24b, and the paint is discharged to the outside of the cylinder 24a, as shown in FIG.

From the process shown in FIG.
When the rotation of No. 1 advances, the process moves to the process shown in FIG.
In this process, the piston 23 is at the bottom dead center and the lowering of the piston 23 is momentarily stopped, as shown in FIG. In this case, as shown in FIG. 2B, the pump cavity 23a is provided with the suction port 24a and the discharge port 2a.
4b. That is, the suction port 2
4 a and the discharge port 24 b are closed by the peripheral wall of the piston 23.

The above is one cycle of the delivery pump 2. Here, by adjusting the rotation speed of the piston 23, the timing of feeding the paint is adjusted. On the other hand, the delivery amount adjusting mechanism adjusts the delivery amount of the paint in one cycle. The adjustment of the stroke can be performed by adjusting the inclination angle of the cylinder 24. The inclination of the cylinder 24 according to the present embodiment is:
This is made possible by connecting the rod 22 bent at a right angle to the rotating drum 21 via a spherical bearing 21b. That is, in the present embodiment, the rotating drum 21 and the rod 22 connected via the spherical bearing 21b, the rod 22 and the piston 23 connected by fixing, the piston 2
The 3 and the cylinder 24 constitute a "stroke changeable mechanism".

An advancing / retracting rod 71 of the tilt cylinder 7 is connected to the cylinder 24 via a swing plate 72. Therefore, by the expansion and contraction of the advance / retreat rod 71,
The swing plate 72 and the cylinder 24 are inclined. That is, the inclination angle of the cylinder 24 can be determined by determining the amount of expansion and contraction of the advance / retreat rod 71. Therefore,
In the present embodiment, the tilt cylinder 7 and the reciprocating rod 7
1. The swing plate 72 connected to the reciprocating rod 71 and fixed to the cylinder 24 is a "stroke determining mechanism".
Is configured.

Next, the relationship between the inclination angle and the stroke will be described with reference to FIG. FIG. 5 is a side view schematically showing the relationship between the inclination angle and the stroke.
(A) shows the case where the inclination angle is small, that is, the stroke is LOW, and (b) shows the case where the inclination angle is large, that is, the stroke is HI. FIG.
In the figure, D indicates the length from the tip of the rod 22 to the bent portion, and α and β indicate the inclination angles. Here, each stroke S
The relationship between T1 and ST2 and the inclination angles α and β is derived by the following equation.

[0029]

(Equation 1)

As can be seen from the equations (1), the stroke of the piston 23 increases as the inclination angle increases. That is, the stroke of the piston 23 can be adjusted by adjusting the inclination angle.

FIG. 6 shows a delivery pump 2A according to the second embodiment, and is a side view schematically showing the relationship between the inclination angle and the stroke, similarly to FIG. In the delivery pump 2A according to the second embodiment, the rod 22A is connected to the outer periphery of the rotary drum 21A via the spherical bearing 21c. This rod 22A projects outward of the rotating drum 21A,
It bends at right angles downward on the way. After that, the rod 22A
After bending to form an obtuse angle, this time bending to the opposite side,
The base end is fixed to the upper end of the piston 23A.

In the delivery pump 2A according to the present embodiment,
When the inclination angle γ is increased, the rod 22 at the top dead center position
The base end of A moves upward (see arrow W1), and the base end of rod 22A at the bottom dead center position moves downward (see arrow W2). That is, as the inclination angle increases, the stroke lengthens. Therefore, the rotating drum 21A and the rod 22A connected via the spherical bearing 21c, the rod 22A and the piston 23A connected by fixing, and the piston 23A and the cylinder 24A in the sliding contact form a "stroke changeable mechanism". I have.

The cylinder 24 according to the present embodiment
The inclination angle of A is determined by the reciprocating rod 71A that expands and contracts by the action of the inclination cylinder 7A. Therefore, also in the present embodiment, the tilt cylinder 7A, the reciprocating rod 71A, and the swing plate (not shown) are
This corresponds to a “stroke determining mechanism”.

The present invention has been described in detail with the delivery pumps 2 and 2A according to the first and second embodiments as examples. However, the present invention is not limited to only this embodiment.
For example, as shown in FIG. 7, the delivery pump may have a structure having two pump functions.

The delivery pump 2B shown in FIG. 7 (a) is provided at one end and the other end of a piston 23B to which a rod 22B similar to the rods 22 and 22A according to the first and second embodiments is fixed. Pump cavities 23a, 23b respectively
Are formed. The cylinder 24B has a suction port 24a corresponding to the pump cavity 23a at one end.
In addition to the pump port 23b, a suction port 24c and a discharge port 24d corresponding to the pump cavity 23b at the other end are provided. The pump cavity 23a at one end is configured in the same manner as the pump cavity 23a according to the above-described first embodiment, and the pump cavity 23b at the other end is positioned about the axis of the piston 23B.
It is formed at a symmetrical position of 0 °. In addition, suction port 2
4a and the discharge port 24b are configured similarly to the suction port 24a and the discharge port 24b according to the first embodiment, and the suction port 24c and the discharge port 24d are
The suction port 24 in the circumferential direction of the cylinder 24B
a and the discharge port 24b.

The delivery pump 2B shown in FIG. 7A has pump cavities 23a, 23b for each half stroke of a reciprocating stroke in which the piston 23B makes one stroke while making one rotation.
Alternately repeat the suction and discharge actions. Therefore, if the two suction ports 24a and 24c are connected to a common suction flow path and the two discharge ports 24b and 24d are connected to a common discharge flow path, a delivery pump with less pulsation can be configured. Can be. In addition, suction port 2
4a and the discharge port 24b are connected to the flow path of the paint, and the suction port 24c and the discharge port 24d are connected to the flow path of the cleaning liquid or the diluent for the paint, so that the paint adhering to the inner wall surface of the cylinder 24B is cleaned Therefore, it is possible to prevent a situation in which the piston 23B is fixed to the inner wall surface of the cylinder 24B by the paint film and the pump operation becomes defective. The shape of the pump cavity 23b corresponding to the suction port 24c and the discharge port 24d connected to the flow path of the cleaning liquid or the diluting liquid is similar to the shape of the pump cavity 23c shown in FIG. The surface may be changed to a shape cut out in a ring groove shape.

The delivery pumps 2 and 2A according to the present embodiment
2B, as described above, the liquid to be delivered is
A material other than paint may be used, and the present invention is also applicable to a case where another liquid is sent out. However, when sending out paint,
In other words, when used in a painting line, it is often necessary to accurately control the amount and timing of feeding the paint. Therefore, a delivery pump embodied according to the invention is preferred.

The delivery pump 2 according to the present embodiment
2A and 2B correspond to cylinders 24, 24A and 24B,
The pistons 23, 23A and 23B rotate and reciprocate. However, the present invention is not limited to this embodiment. For example, a mode in which a reciprocating piston is used as a rotating cylinder is also conceivable. However, if a mechanism for rotating and reciprocating the piston as in the present embodiment is used, the structure is simple, so that the manufacturing is easy and the number of parts is relatively small.

Further, in the delivery pumps 2, 2A, 2B according to the above embodiments, the cylinders 24, 21A are rotatable and supported at predetermined positions with respect to the rotating drums 21, 21A.
The “rotation mechanism” and the “reciprocating mechanism” are configured by inclining 24A and 24B. However, the “rotation mechanism” and the “reciprocating mechanism” can be configured by fixing the cylinder at a predetermined position and rotating the rotary drum while tilting it.

[0040]

According to the present invention, by adjusting the stroke of the reciprocating motion of the piston, it is possible to appropriately adjust the amount of liquid to be sent out. In particular, according to the present invention, it is possible to adjust the timing of sending out the liquid and the amount of sending out separately and independently, so that the control of these sending out states is facilitated and the accuracy of sending out is improved.

[Brief description of the drawings]

FIG. 1 is a schematic side view showing the entire structure of a coating apparatus including a delivery pump according to a first embodiment.

FIG. 2 is a sectional view of a delivery pump, (1) to (4).
Shows the respective steps of the delivery pump for delivering the paint. (A) of each of FIGS. (1) to (4) is a longitudinal sectional view, and (b) is a YY sectional view.

FIG. 3 is a view in the direction of arrow X in FIG. 1;

FIG. 4 is a view in the direction of arrow Z in FIG. 3;

5A and 5B are side views schematically showing a relationship between an inclination angle and a stroke, and FIG. 5A illustrates a case where the inclination angle is small.
That is, the case where the stroke is LOW is shown, and FIG.
This shows a case where the inclination angle is large, that is, a case where the stroke is HI.

FIG. 6 is a side view schematically showing a relationship between an inclination angle and a stroke, which is a delivery pump according to a second embodiment.

FIGS. 7 (a) and 7 (b) are longitudinal sectional views showing other embodiments of the delivery pump, respectively.

[Explanation of symbols]

 1: coating device 2: delivery pump 21: rotating drum 22: rod 23: piston 23a: pump cavity 24: cylinder 24a: suction port 24b: discharge port 7: tilt cylinder 71: reciprocating rod 72: swing plate

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Eiko Tajima 1907, Hirata-cho, Suzuka-shi, Mie Honda Motor Co., Ltd. F-term in Suzuka Manufacturing Co., Ltd. (reference) 3H070 AA07 BB07 CC12 DD24 3H075 AA08 BB03 BB13 CC12 CC30 DA04 DB03 DB22 EE08 EE12 EE17

Claims (1)

[Claims] 1. A cylinder having a suction port and a discharge port formed at corresponding positions in a circumferential direction, a piston having a pump cavity formed in a peripheral wall and sliding in the cylinder, and a rotation mechanism for rotating the piston about an axis. And a reciprocating mechanism for reciprocating the piston in the axial direction. The combined operation of the rotational movement and the reciprocating movement of the piston sucks a liquid into the pump cavity from the suction port and transfers the liquid to the pump cavity. A delivery amount adjusting mechanism for a delivery pump discharging from a delivery port, comprising: a stroke changeable mechanism capable of changing a stroke of the reciprocating motion; and a stroke determination mechanism determining the stroke. The output adjustment mechanism.