JPH0430387Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is characterized in that a plunger is eccentrically arranged in an oil distributor that rotates within a cylinder having an inlet port and a discharge port. The present invention relates to an improvement in an oil pump in which the plunger reciprocates by the undulations of the surface that the outer end surface of the plunger abuts on the circular trajectory of the plunger.

[Prior art] The applicant previously filed Utility Model Application No. 61-112146 and Utility Model Application No. 112146.
No. 57-208, Figures 11 and 1, respectively.
We proposed an oil pump with the configuration shown in Figure 2. 1st
The outline of the configuration will be explained with reference to FIG. 1 and FIG. 12. Reference numeral 1 is a housing in which a cylinder 2 is bored, an oil inlet 3 and an oil outlet 4 are opened in the cylinder 2, and an oil disk is provided. A triviewer 5 is arranged. Rotational motion is applied to the oil distributor 5 by a driving worm 7 via a worm gear 6. The worm gear 6 and the driving worm 7 are arranged outside the pump housing 1 in the configuration shown in FIG. 11, and are built into the housing 1 in FIG. 12. A pump cylinder 8 is eccentrically bored in the oil distributor 5, and a plunger 9 disposed in the pump cylinder 8 is moved along a circular orbit having the eccentricity as a radius by the rotation of the oil distributor 5. The pump action chamber 1 formed by the pump cylinder 8 and the plunger 9 can reciprocate following the ups and downs of the lead cam 13 formed on the lid body 12.
0 is alternately communicated with the suction port 3 and the discharge port 4 via the communication path 11, thereby performing a pumping action. 12th
In the configuration shown in the figure, there is only one communication path 11, whereas in the configuration shown in FIG. This is because, in the latter case, the suction port 3 and the discharge port 4 are located at different axial positions of the oil distributor 5.

The gist of the proposal for the oil pump having the above-described structure is that the lid 12 has a lead cam 13 in addition to its function as a lid, and that the lead cam 13 is formed on the inner and outer surfaces of the lid 12. from,
When the lead cam 13 wears out, it can be used upside down, and the lid 12 can be rotated 180°.
The point is that the suction port and discharge port can be reversed if they are installed offset.

Moreover, in Utility Model Application No. 49-23803, the outer end surface of a plunger that is eccentrically arranged in an oil distributor is rotatably arranged in a pump housing on an extension of the center line of the taste distributor and perpendicular to the center line. A mechanical pump is disclosed in which a rotating shaft is brought into contact with a flat surface formed by cutting out a cutout, and the plunger is reciprocated by using the flat surface as an inclined cam by pivoting the plunger as the distributor rotates.

[Problems with conventional technology] Operating conditions of an engine using an oil pump,
For example, it is not possible to change the discharge amount by changing the reciprocating length of the plunger 9 in response to changes in load, and since the lead cam is made by molding, there are production advantages, but oil discharge There is a problem in that it is difficult to respond to the diversification of quantity requirements.

As an oil pump with variable discharge amount, for example, the first
An oil pump having the configuration shown in FIG. 3 has been conventionally used. The configuration will be schematically explained with reference to FIG. Reference numerals 1 to 12 indicate the same parts as in FIGS. 11 and 12, but the oil distributor 5 performs not only rotational movement but also reciprocating movement, and the pump cylinder 8 is similar to the oil distributor 5. The plunger 9, which is bored concentrically with the pump cylinder 8 and is arranged in the pump cylinder 8, does not reciprocate and remains stationary. 14 is a lead cam formed at the end of the oil distributor 5; 15 is in contact with the lead cam 14, and when the oil distributor 5 rotates,
A guide portion 16 that provides reciprocating motion to the oil distributor 5 is a cam forming portion that contacts a protrusion 17 formed at the center of the end surface of the oil distributor 5 to move the oil distributor 5.
limit the reciprocating length of the The guide portion 15 and the cam forming portion 16 are integrally formed, and the rotation shaft 18
By forming a cam-forming portion 16 and rotating it by a rotary lever 19, the circumferential position of the cam-forming portion 16 in contact with the protrusion 17 changes, thereby limiting the reciprocating length of the oil distributor 5. The discharge amount can be changed by changing the amount. However, in this type of variable discharge amount oil pump, two cam surfaces, the lead cam 14 and the cam forming portion 16 of the rotating shaft 18, must be formed, which is not only disadvantageous in terms of machining time, but also reduces the oil discharge amount. There are many elements to manage, and there are problems with accuracy in controlling the discharge amount.

In the configuration disclosed in Japanese Utility Model Application Publication No. 49-23803, when the reciprocating stroke of the plunger is plotted on the vertical axis and the rotation angle of the oil distributor is plotted on the horizontal axis, it becomes a nearly sinusoidal curve, and the plunger's reciprocating stroke at both ends of the reciprocating stroke is approximately sinusoidal. Since there is no rotational angle range in which the axial movement stops, the plunger continues to reciprocate even when the pump action chamber, suction port, and discharge port are blocked, causing the pressure inside the pump action chamber to abnormally increase, or Not only will this generate a high negative pressure and the required driving torque of the pump during this period will become significantly large, but also oil will leak out or air can enter from the gap between the inner circumferential surface of the pump cylinder and the outer circumferential surface of the plunger. Therefore, there is a problem in that it becomes difficult to accurately control the amount of oil discharged. If the reciprocating stroke of the plunger is taken as the vertical axis and the rotation angle of the oil distributor is taken as the horizontal axis, it must not be a sine curve but must be a trapezoidal curve.

[Means for solving the problem] The plunger 9 rotates as the oil distributor 5 rotates to give reciprocating motion to the plunger, and when necessary, the stroke of the reciprocating motion is changed to adjust the amount of oil discharged. can be changed,
In addition, when the pump action chamber 10 is blocked from the suction port 3 and the discharge port 4, the axial movement of the plunger 9 can be stopped even if the oil distributor 5 is rotating, so the following configuration is adopted. shall be.

[Structure of the invention] A cylinder that is bored in a pump housing and has an oil inlet and an oil outlet; an oil distributor that is placed inside the cylinder and rotates within the cylinder; said oil distributor, wherein said oil distributor is provided with a communication path that alternately communicates said pump cylinder with said suction port and said discharge port by rotation of said oil distributor; a plunger that is slidably arranged and forms a pump action chamber; a spring that biases the plunger in a direction to expand the volume of the pump action chamber;
Means for positioning the axial position of the oil distributor with respect to the pump casing; means that contacts the outer end surface of the plunger and causes the plunger to reciprocate as the plunger pivots due to rotation of the oil distributor; In the oil pump, the cam means has a center line perpendicular to an extension of the center line of the oil distributor, and the oil pump has two circles having different distances from an end surface of the oil distributor. The outer end surface of the plunger is made of a columnar cam in which a columnar surface and a conical surface connecting a step between the two columnar surfaces are arranged adjacent to each other. When the plunger rotates, the plunger is reciprocated by contact between the peripheral edge of the outer end surface of the plunger and the conical surface, and the two cylindrical surfaces and the outer end surface of the plunger The abutment of the plunger forms an axial motion stop period at both ends of the reciprocating stroke of the plunger, and determines the position of the intersection line between the two cylindrical surfaces and the conical surface between the pump action chamber and the suction port. The configuration is such that the position is selected such that the cutoff period with the discharge port falls within the axial movement stop period of the plunger.

[Embodiment] FIGS. 1 and 2 are cross-sectional views showing an embodiment of the oil pump of the present invention, and FIG. 2 is a drawing showing a view of a columnar cam in the direction of the arrow in FIG. 1, which will be described later. be. Reference numeral 101 in Figures 1 and 2
102 is a casing, and 102 is a cylinder bored into the casing. A suction port 103 and a discharge port 104 are open, and an oil distributor 105 is arranged inside. 106 is a pump cylinder which is eccentrically bored in the oil distributor 105;
A plunger 107 is slidably arranged to form a pump action chamber 108. Reference numeral 109 indicates a communication path that communicates the pump action chamber 108 with the suction port 103, and 110 indicates a communication path that communicates the pump action chamber 108 with the discharge port 104. If the suction port 103 and the discharge port 104 are arranged in a straight line, the two communication passages 109 and 110 will be combined. Reference numeral 111 is a lid body on which a columnar cam 112 is arranged. A spring 113 biases the plunger 107 in a direction that separates the outer end of the plunger 107 from the outer end surface of the distributor 105, that is, in a direction that presses the outer end surface of the plunger 107 against the columnar cam 112. Reference numeral 114 denotes an oil reservoir, into which oil is introduced from the suction port 103 through a passage 115 to lubricate the abutting portion between the columnar cam 112 and the outer end surface of the plunger 107. 116 is the oil distributor 10
117 is a guide pin for positioning the axial position of 5 with respect to the housing 101; 117 is the columnar cam 112;
This is a guide pin that determines the axial position of the cover body 111 with respect to the lid body 111.

Next, the columnar cam 112 and the plunger 107 will be explained. The columnar cam 112 has a large diameter portion 11
8 and the small diameter portion 119 are arranged in the axial direction, and a step is formed on the surfaces of both, and a conical surface 1 is formed between them.
20, and the contact portion between the outer end surface of the plunger 107 and the columnar cam 112 is connected to the conical surface 12 between the large diameter portion 118 and the small diameter portion 119.
When moving along zero, a reciprocating movement of plunger 107 takes place. It is preferable that the outer end surface of the plunger 107 and the cylindrical surface of the columnar cam 112 always make contact on the generatrix closest to the oil distributor 105. movement), unless the diameter of the plunger 107 is particularly large enough, a large diameter section 121 is formed at the outer end. Specifically expressed, the radius of the large diameter portion 121 is
Oil distributor 105 and plunger 1
The eccentricity must be larger than the eccentricity with respect to 07, but the details will be described later with reference to the drawings. Plunger 1
If the radius of 07 is larger than the eccentricity, the large diameter part 1
21 is unnecessary.

The cylindrical surface of the large diameter portion 118 and the small diameter portion 11
If the cylindrical surfaces of 9 and 9 are eccentrically formed, the plunger 107 can be rotated by rotating the cylindrical cam 112 with the rotation lever 122.
A large diameter portion 118 and a small diameter portion 119 whose outer end surfaces are in contact with each other.
Plunger 10 by changing the size of the step on the surface.
By changing the reciprocating length of the pump 7, the discharge amount can be made variable. 123 forms a shaft neck for rotating the columnar cam 112.

Next, a design process for determining the shape and dimensions of the columnar cam 112 will be explained in order to enhance the understanding of the structure of the oil pump of the present invention. Figures 3 to 5
The figure shows the position of the pump cylinder 106 from when the suction port 103 to the discharge port 104 begin to open until they finish closing, in terms of the inclination angle with respect to the center line connecting the suction port 103 and the discharge port 104. A chain line 124 indicates the locus of the center line of the pump cylinder 106 when the oil distributor 105 rotates.
The direction of rotation of the oil distributor 105 is indicated by an arrow 125. Angle α of the opening start and closing end of the suction port 103 to the discharge port 104
is determined by the diameter of the oil distributor 105, the diameter of the suction port 103 to the discharge port 104, and the diameter of the communication passage 110 that opens to the oil distributor 105. In FIG. 6, the large diameter portion 118
A method for determining the shape and dimensions of the columnar cam 112 when the small diameter portion 119 and the small diameter portion 119 are concentric, that is, when the oil pump does not have a variable discharge amount will be explained. Reference numerals in the figure indicate the same contents as in FIGS. 1 to 3. The process of determining the shape and dimensions is listed below.

(1) Radius a of large diameter portion 121 of plunger 107
is selected to be larger than the radius of the circle 124 of the locus of the plunger 107 (the amount of eccentricity between the plunger 107 and the oil distributor 105). ).

(2) Draw a circle with the radius a centered on the intersection of the chain line 126 indicating the position α where the discharge port 104 starts to open and the circle 124 of the trajectory.

(3) Draw a solid line 127 at a slight distance δ from the circle with radius a. The value of δ is an allowance for preventing the plunger 107 from starting the discharge stroke before the discharge port 104 begins to open due to dimensional errors during manufacturing.

This may also be considered to be to prevent excessive pressure from being generated in the pump chamber 108 by starting the discharge stroke after ensuring that the opening area is a certain size.

(4) Draw a circle with the radius a centered on the intersection of the chain line 128 indicating the position α when the discharge port 104 finishes closing and the trajectory circle 124. A solid line 129 is drawn at a position within δ from the circle with radius a. δ
The reason why the dimensions are taken is because the discharge stroke is not performed even after the discharge port is closed, or it is preferable that the discharge port 104 is open to some extent even when the discharge stroke is finished.

(5) The diameters of the large diameter part 118 and the small diameter part 119 are determined so that the reciprocating length of the plunger 107 is equal to the difference in radius between the large diameter part 118 and the small diameter part 119, and the large diameter part 118 is defined by the solid line 129. The small diameter portion 119 is drawn on the right side (on the drawing) to the left of the solid line 127, and the conical surface 1 is drawn between the solid line 127 and the solid line 129.
Tie at 20.

The shape and dimensions of the columnar cam 112 are determined by the above.

FIG. 7 is a view (solid line) of the columnar cam 112 of FIG. 6 formed as described above. If the center of the large diameter portion 118 and the small diameter portion 119 is set to 130, then the point 131 is made eccentric by e from the center 130.
The large diameter portion 1 is formed in an arc 132 shape shown by a broken line centered at
By further turning 18, it is possible to make an oil pump with a variable discharge amount in which s is the minimum reciprocating length. Even if the small diameter part 119 and the large diameter part 118 are simply eccentrically turned without turning the large diameter part 118 as shown by the solid line, or even if two cylindrical surfaces with the same diameter are eccentrically turned, there is a difference in level between them. Although the objective can be achieved by forming the cam 112, the existence of the portion indicated by the chain line 133 requires wasted space for the columnar cam 112 to rotate.

FIG. 8 is a view in the direction of the arrow in FIG. 7, and once the large diameter portion 11
8. After turning the small diameter portion 119 and the conical surface 120,
This shows the shape obtained by eccentrically turning by e and further turning into a circular arc 132 shape shown by a broken line. It goes without saying that the structure of the present invention can also be applied to the oil pump having the structure shown in FIG.

[Operation] FIGS. 9a, b, and c are diagrams showing the progress of reciprocating movement of the plunger 107 due to the rotation of the oil distributor 105, and the upper row shows the large diameter of the plunger in a plane perpendicular to the plunger 107. Each position of the portion 121 with respect to the columnar cam 112 is shown, and the lower row shows the axial position of the plunger 107 corresponding to the upper row.

FIG. 10 shows a surface formed by eccentrically turning the large diameter portion 118 that is brought into contact with the outer end surface of the large diameter portion 121 of the plunger 107, thereby reducing the reciprocating length of the plunger 107 and discharging the amount of oil. This is a drawing showing that the discharge amount can be reduced, and since the function of variable discharge amount is clear from the drawing, further explanation will be omitted. In the lower diagram of FIG. 10, the shape before eccentric turning is shown by broken lines.

[effect] The oil pump of the present invention has the following advantages.

(1) Since the columnar cam can be arbitrarily provided with a step by turning to give the plunger a length of reciprocating motion, the configuration shown in Fig. 11 and Fig. 12 in which the plunger is arranged eccentrically to the oil distributor is possible. oil pumps can be easily adapted to meet diversified discharge volume requirements.

(2) By making the two stepped cylindrical surfaces formed on the columnar cam eccentric to each other and arranging the columnar cam so as to be rotatable, as shown in FIG.
The oil pump having the configuration shown in FIG. 12 can have a variable discharge amount.

3. A conventional oil pump with a variable discharge amount has a reed cam 14 that gives reciprocating motion to an oil distributor, as shown in FIG. 13 described above.
, and a control cam 16 for controlling the length of the reciprocating motion, whereas the variable discharge amount oil pump according to the present invention can achieve the purpose with a single columnar cam, which is advantageous in terms of cost. In addition, there is less accumulation of errors in the length of reciprocating motion, less variation in discharge amount, and easier quality control, which further reduces costs.

(4) While the pump action chamber, suction port, and discharge port are blocked, the axial movement of the plunger is stopped and no abnormally high or negative pressure is generated within the pump action chamber, so during this period The required driving torque of the oil pump does not increase significantly, and there is no leakage of oil from the pump action chamber or intrusion of air into the pump action chamber, and the amount of oil discharged can be precisely controlled.

[Brief explanation of the drawing]

FIGS. 1 and 2 are cross-sectional views showing an embodiment of the oil pump of the present invention, and FIGS. 3 to 6 are diagrams explaining the process for determining the shape and dimensions of the columnar cam of the oil pump of the present invention. , FIG. 7 is a view taken in the direction of the arrows in FIG.
Figure 0 is an explanatory diagram of the action. Figure 11, Figure 12,
FIG. 13 shows an oil pump of conventional construction. Explanation of symbols, 101... Housing, 102... Cylinder, 103... Suction port, 104... Discharge port, 1
05...Oil day distributor, 106...
Pump cylinder, 107...Plunger, 108
...Pump action chamber, 109,110...Communication path,
111...Lid body, 112...Columnar cam, 113...
... Spring, 114 ... Oil reservoir, 115 ... Passage, 116, 117 ... Guide pin, 118 ...
Large diameter part, 119... Small diameter part, 120... Conical surface,
121...Plunger large diameter portion, 122...Rotating lever, 123...Shaft neck, 124...Plunger locus.

Claims (1)

[Claims for Utility Model Registration] (1) A cylinder 102 that is bored in the pump housing 101 and has an oil inlet 103 and an oil outlet 104; arranged within the cylinder 102 and rotates within the cylinder 102; A pump cylinder 106 of the oil distributor 105 is eccentrically bored, and rotation of the oil distributor 105 moves the pump cylinder 106 between the suction port 103 and the discharge port 104.
The oil distributor 105 is formed with communication passages 109 and 110 that alternately communicate with the pump cylinder 106; the plunger 107 is slidably disposed within the pump cylinder 106 and forms a pump action chamber 108; a spring 113 that urges the plunger 107 in a direction to expand the volume of the oil distributor 105;
means 116 for positioning with respect to the plunger 101; the means 116 contacts the outer end surface of the plunger 107, and as the plunger 107 rotates due to the rotation of the oil distributor 105, the plunger 1
In the oil pump, the cam means has a center line perpendicular to an extension of the center line of the oil distributor 105, and the oil pump has a center line that is perpendicular to an extension of the center line of the oil distributor 105, and Two cylindrical surfaces 11 with different distances
8, 119 and the two cylindrical surfaces 118, 119
The plunger 1 is composed of a columnar cam 112 adjacent to a conical surface 120 connecting the steps of the plunger 1.
07 is formed into a circular plane having a radius larger than the eccentricity between the plunger 107 and the oil distributor 105, and when the plunger 107 rotates, the outer end surface of the plunger 107 and the conical surface 120 The reciprocating motion of the plunger 107 is performed by the contact between the two cylindrical surfaces 118 and 119 and the outer end surface of the plunger 107, and the reciprocating movement of the plunger 107 in the axial direction at both ends of the reciprocating stroke. forming a motion stop period, the two cylindrical surfaces 11
8, 119 and the conical surface 120, the period of interruption between the pump action chamber 108, the suction port 103, and the discharge port 104 is determined by
The oil pump is located at a position within the axial movement stop period of 7. (2) Utility model registration where two cylindrical surfaces of the columnar cam 112 having different distances from the end surface of the oil distributor have a common center line and are cylindrical surfaces 118 and 119 having different diameters. An oil pump according to claim (1). (3) Different distances of the columnar cam 112 from the end surface of the oil distributor 105 2
The two cylindrical surfaces are mutually eccentric cylindrical surfaces having different center lines, and the cylindrical cam 112 is arranged rotatably around any one of the center lines. An oil pump according to claim (1) of the utility model registration.