JP5874986B2 - Piston of flow meter - Google Patents

Description

  The present invention relates to a piston of a capacity type flow meter provided with a flow pulse transmitting means.

BACKGROUND ART A fuel supply device that supplies fuel oil to a fuel tank of an automobile is provided with a flow meter (for example, see Patent Document 1) for measuring the volume of fuel oil supplied. In such a flow meter, the piston moves in one direction by the fuel oil flowing in from the inlet, and the fuel oil filled in the cylinder on the side where the piston moves is pushed out to the outlet. And if a piston moves to a predetermined position, a piston and a rotary valve will interlock | cooperate and will move a piston in the reverse direction with respect to the said one direction. Then, the volume of the fuel oil is measured (measured) by continuously reciprocating the piston in the one direction and the opposite direction and repeating the reciprocating motion.
The present applicant has proposed a piston that can be used in the flow meter and that can reduce the number of parts and the number of assembly steps (see Patent Document 2).

Such a piston is useful, but since there is no member to hold the seal plate on one side of the seal plate, a small amount of fuel oil leaks when the piston moves, and the metering accuracy by the flow meter decreases. There was a fear.
Further, in order to insert the piston into the cylinder, the seal plate must be held in a curved state so that the seal plate is accommodated in the cylinder, and much labor is required for assembly work. did.
Furthermore, since the above-described piston is a synthetic resin part, the piston has a problem in durability, and there is a possibility that the strength may be reduced by contacting the fuel oil.

JP 7-294304 A Japanese Patent Laid-Open No. 10-142022

  The present invention has been proposed in view of the above-described problems of the prior art, and an object thereof is to provide a flowmeter piston with improved durability without requiring much labor for assembly.

According to the present invention, a metal first plate (41) having a concave portion (41a) radially inward and a metal second plate having a convex portion (42b) engaged with the concave portion (41a) . the plate (42), said first and second radially outer (41c, 42c) of the plate (41, 42) possess a seal plate sandwiched (43), by rotation of the crank shaft (6) In a piston of a flow meter that measures the volume of fuel oil by repeating reciprocating motion in the cylinder, the radially outer sides (41c, 42c) of the first and second plates (41, 42) are respectively measured by the cylinder. The shape is curved toward the inflow side of the target fluid, the radial dimensions of the first and second plates (41, 42) are the same, and the radially inner portion of the seal plate (43) 1st and The first and second plates (41, 42) are accommodated in step portions (41dd, 42du) provided on the radially outer sides (41c, 42c) of the second plates (41, 42). It is sandwiched between regions provided radially outward (41c, 42c).

According to the present invention having the above-described configuration, the seal plate (43) is sandwiched between the radially outer sides of the first and second metal plates (41, 42).
Therefore, the durability of the whole piston (4) is improved, and the fuel oil metering performance by the flow meter is stabilized.

In the present invention, if the radially outer sides (41c, 42c) of the first and second plates (41, 42) are curved, the sealing plate (43) is also formed by the curved shape of the plates (41, 42). It is urged to have a curved shape.
Therefore, it is not necessary to hold the sealing plate (43) in a curved shape by a worker's hand, the labor in assembling work is drastically reduced, and the assembling work efficiency is improved accordingly.

In the present invention, for example, the first and second plates (41, 42) have the same radial dimension, and the sealing plate (43) is provided on the radially outer side (41c, 42c) of the plate. When sandwiched between the first and second plates (41, 42) within (41dd, 42du), the seal plate (43) is pressed from both sides. Therefore, even if the piston (4) moves, the sealing material (43) is not deformed more than necessary, and fuel oil leakage is completely prevented.
As a result, compared with the flowmeter using the piston according to the prior art, the measurement accuracy is improved in the flowmeter using the piston according to the present invention.

It is sectional drawing which shows the flowmeter using the piston which concerns on embodiment of this invention. It is a top view of the piston concerning the embodiment of the present invention. It is XX arrow sectional drawing of FIG. It is explanatory drawing which expands and shows the radial direction outer edge part of a piston.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
First, an example of a flow meter using a piston according to the illustrated embodiment will be described with reference to FIG.

In the capacity type flow meter generally indicated by reference numeral 100 in FIG. 1, the inlet 2i of the upper lid 2 disposed above the main body case 1 is located on the left side, and the fluid to be measured (for example, Fuel oil) passes through the horizontal passage 11L formed in the upper part of the main body case 1 (left region in FIG. 1) from the opening 7i of the rotary valve 7, and receives the pressure receiving surface (FIG. 1) of the left piston 4. In FIG. 1, it flows into the region on the left side (the region on the left side of the piston 4 in FIG. 1) and presses the piston 4 (to the right side in FIG. 1). Then, the left piston 4 moves in the direction of the opposite piston 4 ′ (rightward in FIG. 1), and this movement rotates the crankshaft 6 via the piston rod 5.
When the piston 4 moves in the direction of the piston 4 ′ (rightward in FIG. 1), the right piston 4 ′ moves (rightward in FIG. 1), and the measurement target existing in the right region of the piston 4 ′. The fluid passes through the inside of the rotary valve 7 via the horizontal flow path 11R, and then flows down the vertical flow path 9 below the rotary valve. And it flows out from the outflow port 12 formed in the crank chamber 10 to the outside.

Here, the rotating shaft 61 at the end of the crankshaft 6 is connected to the rotating shaft 71 of the rotary valve 7 by a known means. Therefore, when the pistons 4 and 4 'move rightward by a predetermined distance and the crankshaft 6 rotates 180 degrees (half rotation), the opening 7i of the rotary valve 7 also rotates halfway and the inlet 2i of the upper lid 2 is on the right side. The fluid flow path is switched, and the fluid to be measured flows into the region on the right side of the piston 4 ′.
Thereafter, the above-described operation is repeated, and the pistons 4 and 4 ′ reciprocate linearly, and the crankshaft 6 and the rotary valve 7 rotate.
A flow rate measuring mechanism (not shown) is connected to the rotary valve 7 above the rotary shaft 71 via the connecting shaft 8, and the flow rate measuring mechanism measures the volume of the fluid to be measured corresponding to the rotation amount of the rotary shaft 71. .

The piston according to the embodiment of the present invention is used as the pistons 4 and 4 'in the flow meter described above with reference to FIG.
Next, a piston 4 according to an embodiment of the present invention will be described with reference to FIGS.
2 to 4, the piston 4 is composed of a metal first plate 41, a metal second plate 42, and a seal plate 43.
Although not clearly shown, the seal plate 43 is formed in a flat annular shape as a whole before the piston 4 is assembled. The seal plate 43 is preferably made of a member that has elasticity and is highly resistant to fuel oil.

The metal first plate 41 has a disk shape, and a through hole 41o is formed at the center. As shown in FIG. 3, a convex portion 41b is formed in a radially inner region of the first plate 41, that is, a central region including the through hole 41o. A concave portion 41a is formed on the back surface side (lower side in FIG. 3) of the convex portion 41b.
In the region 41c on the outer side in the radial direction of the first plate 41, the outer edge in the radial direction is curved, and has a shape warped upward in FIGS.

Step portions 41du and 41dd are formed at the boundary between the radially outer region 41c and the radially inner region 41f of the first plate 41 as shown in FIG.
In FIG. 3, in the vicinity of the stepped portion 41du, the upper surface of the radially outer region 41c is lower than the upper surface of the radially inner region 41f. In the vicinity of the stepped portion 41dd, the lower surface of the radially outer side 41c is higher than the lower surface of the radially inner region 41f.

In the illustrated embodiment, the metal second plate 42 has the same shape and the same dimensions as the first plate 41. That is, the 2nd plate 42 is disk shape, the through-hole 42o is formed in the center, and the convex part 42b (refer FIG. 3) is formed in the center area | region containing the said through-hole 42o. As shown in FIG. 3, a convex portion 42b is formed in a radially inner region of the first plate 42, that is, in a central region including the through hole 42o. On the side), a recess 42a is formed.
As shown in FIGS. 3 and 4, the radially outer region 42 c of the second plate 42 also has a shape in which the radially outer edge is curved and warps upward.

As shown in FIG. 3, in the second plate 42, step portions 42du and 42dd are formed at the boundary between the radially outer region 42c and the radially inner region 42f of the region 42c.
In the vicinity of the stepped portion 42du, the upper surface of the radially outer region 42c is positioned lower than the upper surface of the region 42f radially inward of the region 42c. In the vicinity of the stepped portion 42dd, the lower surface of the radially outer region 42c is positioned higher than the lower surface of the radially inner region 42f.

As described above, the first plate 41 and the second plate 42 are formed in the same shape and the same dimensions.
The first plate 41 and the second plate 42 are overlapped in the same direction, and the convex portion 42b of the second plate 42 is engaged (fitted) with the concave portion 41a of the first plate 41. Yes.
As shown in FIGS. 3 and 4, the seal plate 43 is sandwiched between regions 41 c and 42 c on the radially outer side of the first plate 41 and the second plate 42. The inner edge of the seal plate 43 in the radial direction is in contact with the step 41 dd below the first plate 41 and the information step 42 dd of the second plate 42.

As shown in FIGS. 3 and 4, each of the first plate 41 and the second plate 42 having the same shape and the same size has a radially outer edge (above FIGS. 3 and 4). It has a curved shape (toward) and has a sharp point at the radially outer tip.
As shown in FIG. 4, the radial positions (lateral positions in FIG. 4) of the radially outer tip 41 e of the first plate 41 and the radially outer tip 42 e of the second plate 42 correspond ( equal).
Since the radially outer edge is curved (toward the upper side in FIGS. 3 and 4) and the radially outer tip is pointed, the sealing plate is formed by the first plate 41 and the second plate 42. When 43 is sandwiched, the seal plate 43 can be biased so as to be bent to a desired radius of curvature. In addition, the seal plate 43 is pressed to the outer region in the radial direction to prevent the seal plate 43 from being deformed more than necessary during the reciprocating linear movement of the piston 4, thereby preventing fuel oil from leaking from the piston 4. It can be reliably suppressed.

When the piston 4 of the flow meter 100 (see FIG. 1) is assembled, the through hole 42o of the second plate 42 is inserted into the tip 51 of the piston rod 5 in FIG. Then, the seal plate 43 is engaged with the second plate 42 so that the radially inner end portion of the seal plate 43 abuts on the upper step portion 42 du of the second plate 42.
With the seal plate 43 engaged with the second plate 42, the first plate 41 is oriented in the same direction as the second plate 42, and the concave portion 41 a of the first plate 41 is changed to the convex portion 42 b of the second plate 42. The piston rod 5 is inserted (inserted) into the front end portion 51 of the piston rod 5.
Then, in a state where the seal plate 43 is sandwiched between the first plate 41 and the second plate 42, the lock nut N is screwed into the male screw of the tip portion 51 of the piston rod 5, and tightened with an appropriate torque. A total of 100 pistons 4 are assembled.

According to the illustrated embodiment, the seal plate 43 is sandwiched between the metal first plate 41 and the second plate 42 in the radial direction. There is no need to use synthetic resin (which has problems with oil).
Therefore, when used in a fuel oil flow meter, the durability of the piston 4 is improved, and the deterioration of the flow rate measurement accuracy due to the deterioration of the piston 4 to the fuel oil can be prevented. Is stable.

In the illustrated embodiment, the outer edges of the radially outer regions 41c, 42c of the first plate 41 and the second plate 42 are curved, and the first plate 41 and the second plate 42 are curved. Since the outer edge in the radial direction has a sharp shape, the seal plate 43 is also urged into a curved shape along the outer edge in the radial direction of the plates 41 and 42 (so-called “fake” is applied).
For this reason, it is not necessary to hold the seal plate 43 in a curved shape by a worker's hand, the labor in assembling work is drastically reduced, and the assembling work efficiency is improved accordingly.

In the illustrated embodiment, the shape and radial dimension of the first plate 41 and the second plate 42 are the same, and the seal plate 43 is sandwiched between the first plate 41 and the second plate 42, and the seal plate 43 The seal plate 43 is the same from both the first plate 41 and the second plate 42 (from both sides) by arranging the inner edge in the radial direction so as to contact the step portions 41 dd and 42 du provided on the plates 41 and 42. It becomes a structure that can be pressed down. Therefore, even if the piston 4 reciprocates linearly in the flow meter 100, the seal material 43 is not deformed more than necessary, and fuel oil is prevented from leaking from the piston 4.
As a result, as compared with the flowmeter using the piston according to the prior art, the flowmeter using the piston 4 in the illustrated embodiment improves the measurement accuracy.

  Further, in the illustrated embodiment, since the first plate 41 and the second plate 42 are the same member, the manufacturing cost can be reduced and the management cost can be suppressed.

  It should be noted that the illustrated embodiment is merely an example, and is not a description to limit the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Main body case 2 ... Upper cover 3 ... Cylinder 4 ... Piston 5 ... Piston rod 7 ... Rotary valve 8 ... Connection shaft 9 ... Vertical flow path 10 ... Crank chamber 41 ... first plate 42 ... second plate 43 ... seal plate

Claims (1)

A metal first plate (41) having a concave portion (41a) radially inward, and a metal second plate (42) having a convex portion (42b) engaged with the concave portion (41a) the first and second radially outer (41c, 42c) of the plate (41, 42) possess a seal plate sandwiched (43), a reciprocating motion within a cylinder by the rotation of the crank shaft (6) In the piston of the flow meter that measures the volume of the fuel oil by repeating, the radially outer sides (41c, 42c) of the first and second plates (41, 42) are respectively on the inflow side of the fluid to be measured of the cylinder. The first and second plates (41, 42) have the same radial dimension, and the radially inner portion of the seal plate (43) has the first and second plates. plate 41, 42) radially outward (41c) of the first and second plates (41, 42) in a state of being accommodated in a step (41dd, 42du) provided on the radially outer side (41c, 42c). 42c) is sandwiched between regions provided in 42c).

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