JPS60143719A - Multiple-point contacting noncircular gear for rotary piston - Google Patents

Abstract

PURPOSE:To make it possible to measure an accurate flow rate, by specifying the profile curves of an internal gear and an external gear, reducing a slip ratio, thereby obtaining substantially perfect rolling contact. CONSTITUTION:A rotary piston is constituted of an internal gear 1, which has a pitch curve of N lobes and constitutes a cabinet, and an external gear 4, which operates as a valve for output and input ports 2a and 3a of the cabinet and has the pitch curve of (N-1) lobes. The profile of the internal gear 1 is determined by the envelop of the small curve, which is protruded to the outside of the pitch curve around the top of the pitch curve of the external gear 4, and the pitch curve of the external gear 4. Said small curve is obtained when the pitch curve of the external gear 4 rolls on the pitch curve of the internal gear 1 without slipping. The profile of the external gear 4 is determined by the envelop of the profile of the internal gear 1, which is drawn on a plane fixed to the external gear 4.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel multi-point contact non-circular gear for a rotating piston, particularly suitable for use as a positive displacement flow needle.

In addition to the twin rotor type, which is typically a non-circular gear type, various types of positive displacement flow rate needles have been put into practical use, including vane type, rotating piston type, oscillating piston type, and reciprocating piston ring type. For example, a highly accurate and sensitive flow rate needle that can directly measure the gas flowing at a small flow rate or the fuel consumption of an automobile while driving and use it for engine control has not been proposed.

Automotive fuel has a low viscosity and a low flow rate of about 1/hr or less, so the flow rate cannot be measured using anything other than a small reciprocating piston type flow needle or a minute flow rate measuring device equipped with a special rotor drive control device. Although needles have difficulty measuring in these areas, these instruments are not suitable as fuel needles for vehicles.

On the other hand, today, car electronics for the purpose of reducing fuel consumption in general trunks, buses, passenger cars, etc., countering exhaust gas pollution, and improving driving safety is rapidly progressing. This has been hampered by the inability to accurately measure the amount of fuel injected.

In order to equip a general commercial vehicle with such a fuel injection needle, the flow meter must be inexpensive, and must also have low pressure loss so as not to affect the characteristics of the carburetor and engine. However, it is required that the function will not stop due to contaminants in the liquid being measured. However, the above-mentioned reciprocating piston type flow needle cannot meet these requirements.

The present invention has been made from the viewpoint of the above,
The purpose of this is that the movable part is a single member, has a small mass, and does not require a shaft, pilot gear, cam, etc. to regulate its movement, and the only internal gear that is the inner wall of the casing. It is configured as an external gear restrained by a chisel, and the tooth profile curves of the internal gear and the external gear both have shapes similar to their respective pitch curves,
Therefore, the tooth surfaces of both gears perform ideal meshing motion with almost no relative sliding motion. Therefore, when this is used as a positive displacement flowmeter, it operates sharply and
A novel rotating system that is highly accurate, can measure various high and low viscosity fluids with little pressure loss over a wide flow range from minute flow rates to large flow rates, is less susceptible to interference from foreign objects, and can be manufactured at low cost. An object of the present invention is to provide a multi-point contact non-circular gear for a piston.

Therefore, the gist of the present invention is to provide an internal gear having an N-shaped pitch curve and serving as a casing, and an internal gear that rotates inside the casing.
In a rotary piston consisting of an external gear with an (N-1) leaf-shaped pitch curve that operates as a valve for the inlet/outlet boat of the housing, the tooth profile curve is similar to a pinch curve, so the slip rate is extremely low. The object of the present invention is to construct a novel multi-point contact non-circular gear for a rotating piston that is small in size and has substantially perfect rolling contact.

Therefore, the above purpose is to calculate the tooth profile curve of an internal gear by calculating the area around the apex of the pitch curve of the external gear when the pitch curve of the external gear rolls on the Bi-Sochi curve of the internal gear without slipping. The tooth profile of an internal gear is determined by the envelope of the pitch curve of the external gear and a small curve convex to the outside of the pitch curve drawn in This is achieved by defining the envelope of the curve.

The present invention will be described in detail below based on the drawings.

FIG. 1 is a front view showing an embodiment of a flow rate needle constructed using a multi-point contact non-circular gear for a rotary piston according to the present invention;
Fig. 2 is a sectional view taken along section line A-A in Fig. 1, Fig. 3 is an explanatory diagram of the pitch curve of the internal gear and the pitch curve of the external gear, and Fig. 4 is a cross-sectional view of the internal gear. Explanatory diagram of cross-sectional tooth profile,
Figure 5 is an explanatory diagram of the cross-sectional tooth profile of the internal gear, Figure 6 is an explanatory diagram showing the position and shape of the boat, Figures 7 and 7 are explanatory diagrams showing the shape of the flow path provided in the rotor, and Figure 8 11 to 11 are explanatory diagrams showing the relationship between the rotation of the rotor and the boat.

In each figure, 1 is a measuring chamber member, 2 and 3 are end members, 2a,
3a is a boat provided on the end members 2 and 3, respectively, 4 is a rotor, 5 and 6 are piping connection members, 7.7 is a bolt, 8.8 is a nut, and 9.9t is an O-ring.

The measuring material 1 has a four-lobed internal tooth whose tooth profile curve is defined by the method described later. It is an i-gear whose openings at both ends are closed by end face members 2 and 3, and a space inside the internal gear forms a measuring chamber.

The end members 2 and 3 are provided with boats 2a and 3 each having a square cross section and opening facing each other toward the measuring chamber.
a, and piping connections 2C and 3C leading to these boats 2a and 3a are provided, and these piping connections 2
Appropriate pipe connection members 5.6 are attached to C and 3C, respectively.

The rotor 4 is an external gear having trilobal external teeth that mesh with the internal teeth of the measuring chamber member 1, and is provided within the measuring chamber member 1.
Bo) The flow path between 2a and 3b is blocked, and the pressure of the fluid flowing between them is applied to perform planetary motion in the metering chamber member 1, which is a combination of revolution in a certain direction and rotation.

The outer contour line of the rotor 4 and the inner contour line of the weighing chamber are always in contact at a plurality of points, so that the space between the inner surface of the weighing chamber member 1 and the outer surface of the rotor 4 always has a plurality of measuring chambers. Each chamber is divided into chambers, and each of these chambers alternately expands and contracts by the meshing movement of the rotor 4 with the measuring chamber member 1, and when the expansion process changes to the contraction process, the capacity of each chamber reaches its maximum. On the other hand, when the contraction process changes to the expansion process, the capacity of the chamber becomes substantially O.

The rotor 4 has a central partition wall 4C, on one side of which are three channels 4a, 4, leading from the metering chamber to the boat 2a.
a', 4a'' are provided rotationally symmetrically, and on the other side,
The same shape as the above-mentioned flow paths 4a, 4a', 4a'' with the front and back reversed, i.e.,
Channels 4b, 4b', and 4b'' are provided symmetrically about the central axis of the trilobal shape.

The shapes of these flow paths and boats are such that each of the plurality of sections of the measuring chamber is always in a bow position according to the phase of the rotor 4.
A or 3a is formed so as to be connected to only one of the twists.

Each chamber formed between the inner surface of the metering chamber member 1 and the outer surface of the rotor 4 is connected to the boat 2a through the above flow path when it is in the expansion process, and to the boat 3 when it is in the contraction process.
Therefore, the rotor 5 can rotate smoothly as a rotating piston, and the fluid flows to the bow) 2a.
It will be transported from there to 3a.

That is, the rotor 4 divides the inside of the needle amount chamber into a plurality of chambers,
It acts as a valve to cut off and seal direct fluid communication between bow) 2a and 3a, and to switch communication between bow) 2a and 3a with a plurality of chambers divided within the measuring chamber, and to adjust the needle amount. It rotates at an angular velocity proportional to the volumetric flow rate of the fluid flowing through the chamber.

When used as a flow rate needle, this rotation of the rotor 40 can be detected by a known pickup and counted by a counting device to display the instantaneous flow rate or cumulative flow rate.

Next, an example of the inner contour line of the metering chamber member 1, that is, the tooth profile of the internal gear in a cross section perpendicular to the axis, will be described with reference to FIGS. 3 and 4.

In the following drawings, the center of the metering chamber member 1 is set to 0, and the metering chamber member 1 has the origin at point 0 on the axis-perpendicular cross section of the metering chamber member 1.
The coordinate axes fixed to are the X axis and Y axis.

To determine the cross-sectional tooth profile of the internal gear, first, measure chamber member 1
An appropriate square is set on the axis-perpendicular cross section with the origin O as the intersection of the diagonals, and this is defined as the pinch curve of the internal gear.

Next, it is surrounded by three outwardly curved arcs with a length equal to one side of this square, and the angle formed by the tangents of two adjacent arcs drawn at each vertex is one side of the square. A trefoil shape with two interior angles, that is, 90 degrees, is determined, and this is defined as the pitch curve (■) of the external gear.

Such a trefoil figure is an equilateral triangle PQR that draws an arc with a radius r and has an arc length equal to the length 21 of one side of the square, and whose side is a line segment connecting two points at both ends of this arc. It is obtained by drawing this equilateral triangle and surrounding it with a circular arc of radius r passing through each vertex of this equilateral triangle.

If 2α is the central angle for the above circular arc, then r=It/α From the above two conditions, α becomes n/12.

Next, the above-mentioned trefoil figure obtained in this way is inscribed in this so that the midpoint of one of the arcs QR coincides with the midpoint of one side of the above-mentioned square (the position shown in FIG. 3), and the above-mentioned Draw a small curve around the vertex P that faces the arc QR.

In the illustrated embodiment, this small curve is a small circular arc S centered on the vertex P and inscribed in the square.

Next, furthermore, this small circle S is centered around each vertex of the above figure.
Add small arcs T and U with the same radius as the arc, and call this figure ■.

In this embodiment, a small arc inscribed in the square is shown as the small curve, but this curve is not limited to a circular arc, and may be an ellipse or other quadratic curve, a sine curve, etc. Alternatively, the curves may be asymmetrical with respect to the central axis of the trilobal shape, such as a spiral, and these curves are not necessarily required to be tangent to the square.

Therefore, the cross-sectional tooth profile of the internal gear is determined by the envelope of the above figure ■ when the pitch curve ■ of the external gear rolls on the pitch curve 1 of the internal gear without slipping. be.

In other words, the two adjacent circular arcs of the above figure (■) are inscribed in the two adjacent sides of the above square, and from this position the above figure H is inscribed.
When a rolling motion is applied to the square, an envelope generated on a plane perpendicular to the axis fixed to the metering chamber member 1 is a curve that defines the cross-sectional tooth profile of the internal gear.

Figure 4 shows the shape ■ determined based on the above method, and the rotor 4
The solid line, one-dot chain line, two-dot chain line, and broken line show the state when the gear is sequentially rotated clockwise by 15 degrees, and the cross-sectional tooth profile of the internal gear can be immediately understood from this.

In this embodiment, the tooth profile curve of the internal gear is the small arc P.
It turns out that it is determined only by SQ and H.

Next, the outer contour line in the axis-perpendicular cross section of the rotor 4, that is, the cross-sectional tooth profile of the external gear will be explained.

The cross-sectional tooth profile of the external gear is the envelope of the cross-sectional tooth profile of the internal gear on the plane fixed to the rotor 4 when the pitch curve of the external gear rolls on the pitch curve of the internal gear without slipping. This is obtained as follows.

FIG. 5 shows the inner contour line of the metering chamber member 1 determined based on the above method, which appears on a cross section perpendicular to the axis fixed to the rotor 4 when the rotor 4 sequentially rotates 15 degrees counterclockwise. The inner contour lines of the metering chamber member 1 are shown by solid lines, one-dot chain lines, two-dot chain lines, and broken lines, respectively, from which the shape of the outer contour line of the rotor 4 can be immediately understood.

Next, the relationship between the position and shape of the port and the position and shape of the flow path provided in the rotor 4 will be explained with reference to FIG. 6.

In FIG. 6, the shape of the port provided in the end face member 2 is added to the inner contour line of the metering chamber member 1.

The end face member 2a has a square shape with the center 0 of the measuring chamber member 1 as the center and each vertex on the X axis and the Y axis.

The port 3a is provided in the end member 3, and the port 2a
It is in a symmetrical position.

Therefore, the shape of the flow path provided in the rotor 4 is
This is determined by the relationship between the ports 2a and 3a when the above-mentioned meshing movement occurs.

FIG. 7 shows the cross-sectional tooth profile of the internal gear that occurs on the plane fixed to the rotor 4 when the rotor 4 performs the above-mentioned meshing motion and rotates by 30 degrees, using a solid line, a dashed-dotted line, and a dotted line. 1. The positions of ports in each state are shown with broken lines.

The shape of the flow path provided in the rotor 4 is defined by connecting the contour lines that overlap with the port 2a in the state when the rotor 4 has rotated to 30 degrees, as shown in FIG. 7, as shown in the figure. do.

Providing the ports in this way allows the above-mentioned respective chambers to smoothly expand and contract, allowing the rotor 5 to operate as a rotating piston.

Here, the relationship between the rotation of the rotor 4 and the ports will be explained with reference to FIGS. 8 to 11.

8 to 11, the rotor 4 is located within the measuring chamber member 1.
It is an explanatory view showing a state when it rotates to a certain degree.

As shown in FIGS. 8 to 11, the rotor 4 always makes contact with the inner wall of the measuring chamber member 1 at three or four points to divide the inside of the measuring chamber into a plurality of chambers and perform meshing motion. . At this time, each chamber communicates with the port 2a provided on the end member 2 when it is in the expansion process, and communicates with the port 3a provided on the end member 3 when it is in the contraction process, so that the fluid flows through the port 2a.
It will be transported from there to 3a.

In this way, the rotor 4 blocks and seals direct fluid communication between the ports 2a and 3a, and switches communication between the ports 2a and 3a and a plurality of chambers divided within the needle volume chamber. It operates as a valve and rotates with an angular velocity that is proportional to the volumetric flow rate of the fluid flowing inside the needle metering chamber.

In order to detect 40 rotations of the rotor, a large number of permanent magnets with magnetic poles arranged at equal intervals along a cross section perpendicular to the axis of the rotor 5 are provided, and an appropriate pickup is placed on the measuring chamber member 1 or the end face member 2 or 3. Each time these permanent magnets pass through the pickup, it is extracted as a pulse signal, and this signal is counted by a counting device.

The rotor 4 is extremely lightweight and does not require any other parts to rotatably support it and make it perform planetary motion.

Furthermore, when the flow rate needle is constructed using the multi-point contact non-circular gear for a rotary piston according to the present invention, the rotor comes into almost complete rolling contact with the wall of the metering chamber. It operates extremely sensitively, and even if there is some foreign matter in the fluid to be measured, it is unlikely to stop functioning due to foreign matter, and even with low viscosity fluids such as gasoline and liquefied gas, it can be used with a large flow rate to a very small flow rate. It is possible to accurately measure the flow rate over a wide range of flow rates.

Note that the configuration of the present invention is not limited to the embodiment on the ridge.

For example, in the above description, the N-shaped shape set as the pitch curve of the internal gear in order to define the inner contour line in the axis-perpendicular cross section of the metering chamber member was shown as a square as an example. This may be any convex or concave curve with non-straight sides, such as a pincushion shape, a drum shape, etc., consisting of a sine curve, a quadratic curve, or any other curve, and each vertex of a regular N-gon has a sharp point. In addition, even in the above embodiment in which the pitch curve of the internal gear is square, for example, the shape of the pitch curve of the external gear satisfies the rolling condition. If so, it may be of any shape, and there are no particular restrictions on the small curve drawn around the apex, that is, the intersection of the pitch curve and the central axis of the multilobed shape. In short, these shapes and dimensions can be freely selected within the scope of the purpose of the present invention.

Furthermore, N is not limited to 4, but any integer of 3 or more can be adopted, and based on these, a rotating piston can be constructed in the same manner as in the above embodiment, and in that case, The shape of the space provided in the boat and the rotor, which serves as a flow path, is changed as appropriate.

In addition, the shapes of other components, coupling methods, etc. can be freely changed within the scope of the purpose of the present invention. For example,
In the above embodiment, the metering chamber member and both end members are separate members, but they can be combined as appropriate and integrated into a composite. In addition to flowmeters, the present invention can also be used in pumps, motors, and other machines, and the present invention encompasses all of them.

[Brief explanation of the drawing]

FIG. 1 is a front view showing an embodiment of a flow rate needle constructed using a multi-point contact non-circular gear for a rotary piston according to the present invention;
FIG. 2 is a cross-sectional view taken along the line @A-A in FIG. Figure A, Figure 4 is an explanatory diagram of the cross-sectional tooth profile of the internal gear, No. 5m is an explanatory diagram of the cross-sectional tooth profile of the internal gear, and No. 6 is an explanatory diagram of the cross-sectional tooth profile of the internal gear.
wA is an explanatory diagram showing the position and shape of the boat, No. 7IIl
1 is an explanatory diagram showing the shape of a flow path provided in one trochanter, and FIGS. 8 to 11 are explanatory diagrams showing the relationship between the rotation of the rotor and the boat. 1. ...---m-Measuring chamber member 2.
3-...----1... End member 4------
−・・−−1−−−−Rotor patent applicant Length 1) Heavy
Kei Agent (7524) Mogami Shota Section Figure 2 32 Figure 1 Figure 4 Figure 3 Figure 6■ Figure 7＼；Figure 5, Figure 10, 7 Figure 8

Claims (1)

[Scope of Claims] (An internal gear having an 11N lobe-shaped pitch curve (N is an integer of 3 or more); and an internal gear having an (N-1) lobe-shaped pitch curve, which is inscribed in the internal gear and meshes with the above-mentioned internal gear. and a moving external gear, and the peak of the pinch curve of the external gear when the pitch curve of the external gear rolls without slipping on the pinch curve of the internal gear. is defined by the envelope of a small curve convex to the outside of a pitch curve drawn around the pitch curve of the external gear, and the tooth profile curve of the external gear is drawn on a plane fixed to the external gear. A multi-point contact non-circular gear for a rotating piston, characterized in that it is defined by an envelope of a tooth profile curve of an internal gear. (2) A multi-point contact non-circular gear for a rotating piston according to claim 1, wherein N is 4 Circular gear. (3) The rotary piston according to claim 2, wherein the pitch curve of the internal gear is square. (4) A convex portion on the outside of the pitch curve drawn around the apex of the pitch curve of the external gear. The multi-point contact non-circular gear for a rotary piston according to any one of claims 1 to 3, wherein the small curved line is a small circular arc.