JPH10115148A - Door closing speed control valve for door closer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply regulate door closing speed by advancing and retreating a regulation shaft housed in the housing hole of a housing, increasing and decreasing the insertion length of the edge of a spool shaft into the spool hole of the V-shaped groove and varying flow resistance of working oil. SOLUTION: A screw hole 25 and a housing hole 26 are successively provided in the center of the housing 20 of the cylinder cap 10 of a dash pot type control valve, and a spool bearing 23 having a spool hole 24 is fitted to a recess part at the side of a cylinder. The regulation shaft 30 is screwed in the housing hole 26, the edge of a spool shaft 32 forming a V-shaped groove 31 is inserted in the spool hole 24. Since the cross sectional area of the V-shaped groove 31 is very small, at the time of closing a door, large flow resistance at the time when working oil pushed by the cylinder is flowed from the spool hole 24 to a space 28 is produced, and movement speed of a piston is reduced to a practically sufficient speed. Even if viscosity of working oil is changed by temperature difference, a tool is engaged to the slot 36 of the head part 35 of the regulation shaft to be rotated, the length of the V-shaped groove 31 is changed for the spool hole 24, and closing speed can be simply regulated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a door closer having a dashpot-type spring buffer mechanism using hydraulic oil.

[0002]

2. Description of the Related Art An example of a conventional door closer often used is disclosed in Japanese Utility Model Laid-Open No. 2-85780.

[0003] In this closer, an excessive closing force due to a return spring and inertia when the door is closed is damped and damped by the fluid resistance of hydraulic oil. A first chamber and a second chamber rearward, and a first chamber and a second chamber via an orifice.
A conducting path communicating with the chamber, a return spring for urging the piston toward the first chamber, a rack provided on the piston,
It comprises a pinion that meshes with the rack, and a rotating shaft that is supported by the cylinder and to which the pinion and the arm are fixed.

[0004]

However, in the above-described conventional closer, the closing movement of the closer is damped by utilizing the fluid resistance when the hydraulic oil passes through the orifice, so that the temperature change of the environment may be reduced. As a result, the viscosity of the hydraulic oil also greatly changes. Therefore, in order to keep the closing time of the door substantially constant, it is necessary to adjust the adjusting valve according to a change in the temperature of the environment.

[0005] However, since the door closer is usually mounted on the upper part of the door and the adjustment of the adjustment valve requires a special tool, it is impossible for a general user to operate the adjustment valve. In fact, it was unavoidable that the closing time of the doors had been left to change as the seasons changed.

Accordingly, the present invention has been proposed for the purpose of improving the shape of the orifice of the regulating valve so that the closing time of the door does not change significantly even when the viscosity of the hydraulic oil changes due to a change in the temperature of the environment. It is a thing.

[0007]

In order to achieve the above-mentioned object, the present invention provides a V-shaped groove at the shaft tip which is deepest at the shaft end and which becomes linearly shallower toward the base of the shaft. In the dashpot type regulating valve composed of a spool shaft formed along the generatrix and a spool bearing fitted with the spool shaft, the depth of the V-shaped groove at the spool shaft end position is equal to or larger than the radius of the spool shaft. Is set.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in the drawings. FIG. 1 shows a cylinder cap 1 having a dashpot type adjustment valve for a door closer.
0 is a longitudinal sectional view, and has a housing 20 and an adjustment shaft 30.

A screw 21 is formed on the outer periphery of the housing 20 and is screwed and attached to a tubular door closer body (not shown).

A right end of the housing 20 in FIG. 1 faces a cylinder (not shown), and a filter 22 and a spool bearing 2 are formed in an unnumbered recess formed in the end surface thereof.
3 are fitted.

A spool hole 24 is formed in the center of the spool bearing 23 so as to penetrate the spool bearing 23 and fit with a spool shaft described later.

On the other hand, a screw hole 2 is provided at the center of the housing 20.
5 and a housing hole 26 are coaxially connected, and an oil guide hole 27 is formed in the center of the housing 20 so as to penetrate the housing 20 in the radial direction and open an inner end to the screw hole 25.

An adjusting shaft 30 housed coaxially with the housing 20 has a spool shaft 32 having a V-shaped groove 31 formed at its tip (the right end in FIG. 1) along its generatrix, and an outer peripheral surface having the V-shaped groove 31. Base 3 having external thread formed to screw into screw hole 25
3 and a head 35 in which a packing 34 is fitted.

A slot 36 for engaging a tool such as a driver is formed on the outer end surface of the head 35. The adjustment shaft 30 is rotated by engaging the tip of the tool with the slot and rotating the tool. be able to.

Since the adjusting shaft 30 is screwed into the screw hole 25 as described above, the adjusting shaft 30 is rotated in the cylinder cap 10 to rotate the adjusting shaft 30 in the front-rear direction (the left-right direction in FIG. 1). Can be moved.

When the door is closed, the piston in the cylinder is pushed to the left by the force of a return spring (not shown), and the hydraulic oil pushed by the piston passes through the filter 22 and passes through the arrow 4.
As shown in FIG. 1, the fluid flows into the spool hole 24 of the spool bearing 23.

The operating oil flowing into the spool hole 24 is V
Through the groove 31 and into the space 28 between the screw hole 25 and the spool shaft 32, and as shown by the arrow 42, the oil guide hole 2
7, and is returned to the low pressure side of the cylinder via a conduction path (not shown).

When the hydraulic oil passes through the V-shaped groove 31, the cross-sectional area of the V-shaped groove 31 is very small, so that a large fluid resistance occurs here and the moving speed of the piston is reduced to a speed sufficient for practical use. It is possible to make it.

As described above, the distance between the inner end surface 23a of the spool bearing 23 (see FIG. 2) and the distal end surface 32a of the spool shaft 32, that is, the insertion length of the spool shaft 32, is determined as described above. It can be adjusted by rotating the head 35.

Therefore, by increasing or decreasing the insertion length, the V-shaped groove 31 in the spool hole 24 through which the hydraulic oil passes is provided.
Can also be adjusted, so that the hydraulic resistance of the hydraulic oil can be adjusted, and consequently the door closing speed can be adjusted.

Note that, depending on the type of the closer, there is an adjusting valve in which the flow direction of the hydraulic oil is opposite to the arrows 41 and 42 in FIG.

The above is the general structure of the adjusting valve of the dashpot type shock absorbing mechanism, which is known in the industrial field related to door closers, and further detailed description of the structure will be omitted.

Next, the fluid resistance generated when the hydraulic oil passes through the V-shaped groove 31 will be described.

In this case, the fluid resistance consists of two fluid resistances, one of which is shown in FIG. 2, in which the hydraulic oil is filled with a fan whose upper part is surrounded by an arc of the hole 24 and whose lower part is surrounded by a V-shaped groove. This is a pipe friction resistance (choke resistance) R1 when flowing through a pipe having a cross section of a shape.

This pipe frictional resistance is applied from the leading end face 32a of the spool shaft 32 to the end face 23a of the spool bearing 23. According to the teaching of fluid dynamics,
The pipe frictional resistance R1 of the circular pipe is expressed by the following equation.

[0026]

(Equation 1)

Where λ is the coefficient of friction of the pipe,
It is greatly related to the flow velocity, the inner diameter of the pipe, and the surface roughness of the pipe, and the value of λ increases as the viscosity increases. Also, l is the length of the pipe, d is the inner diameter of the pipe, v is the flow velocity, and g is the acceleration of gravity.

In the case of a V-shaped groove, the above equation does not apply as it is because the cross section is not a circular pipe, but it can be applied by selecting the value of the inner diameter d to a value corresponding to the V-shaped groove.

As shown in FIG. 3 and FIG. 4, the other one of the fluid resistance is that the hydraulic oil flows into the space 28 from an opening 37 in which the spool bearing end face 23a is formed from a groove cross section that cuts the V-shaped groove 31. Is the resistance (orifice resistance) R2 of the suddenly changing section when flowing out.

As shown in FIG. 4, the opening 37 is
The upper part is an arc of the spool hole 24 and the lower part is a V-shaped fan.

According to the teaching of hydrodynamics, the resistance R2 of the suddenly changing section is expressed by the following equation.

[0032]

(Equation 2)

Here, ξ is a constant determined by the shape of the suddenly changing section, and is assumed to be substantially equal to 1. Also, v
_1, v ₂ is the flow velocity of the fluid before and after cross-fluctuating parts, g is the acceleration of gravity.

In the two fluid resistances described above, the pipe frictional resistance R1 is related to the viscosity of the fluid as described above.
It is clear from the above two equations that the sudden change section resistance R2 is not related to the viscosity.

Next, the V-shaped groove 31 employed in the regulating valve of the present invention will be described. FIG. 5 shows a vertical cross section of a V-shaped groove 31 according to the present invention.
The length 1 and the symbol H1 indicate the maximum depth of the V-shaped groove 31, and this maximum depth H1 is equal to the depth at the distal end surface 32a of the spool shaft 32. Reference symbol D indicates the diameter of the spool shaft 32.

As for the manufacturing dimensions, the diameter D is 4.5 mm.
In the case of (mm), the length X is 3.5 mm, the maximum depth is 2.25 mm, and the angle of the V-shape is 60 °.

The maximum depth of 2.25 mm is 4.5 mm in diameter.
, Which is significantly larger than the maximum depth of the V-shaped groove employed in a conventionally used regulating valve described later.

By increasing the maximum depth H1 of the V-shaped groove, the cross-sectional area of the V-shaped groove 31 increases, the equivalent pipe diameter d in the equation of the pipe frictional resistance R1 increases, and the flow velocity v decreases. Become smaller.

Therefore, the pipe frictional resistance R1, which is inversely proportional to the pipe diameter d and proportional to the square of the flow velocity v, becomes very small.

On the other hand, in order to set the door closing time to a predetermined value, the fluid resistance must be set to a constant value, and the total value of the pipe friction resistance R1 and the sudden section change resistance R2 is set to a constant value. It is necessary to keep.

Therefore, the resistance R2 of the V-shaped groove in the present invention is set so as to increase as the pipe friction resistance R1 decreases.

As a result of the above, the influence of the pipe frictional resistance R1, which is affected by the viscosity of the hydraulic oil, becomes small, and the change in the closing time of the door becomes small even if the viscosity of the hydraulic oil increases or decreases.

FIG. 7 is a vertical cross section of a V-shaped groove employed in a conventionally used regulating valve.
The figure shows the maximum depth of the groove, and other symbols are the same as those described in FIG.

As the manufacturing dimensions, when the diameter D is 4.5 mm, the length X is 3.5 mm, the angle of the V-shape is 60 °, and the maximum depth is 1.7 mm. 0.525 mm smaller than the maximum depth of the groove of 2.25 mm.

As described above, in the conventional regulating valve, since the depth of the V-shaped groove is relatively shallow, the pipe frictional resistance R1 generated in the V-shaped groove is relatively large, and the resistance R in the suddenly changing section is generated.
2 occurs small.

Therefore, the influence of the pipe frictional resistance R1 which affects the viscosity of the hydraulic oil increases, and when the viscosity of the hydraulic oil increases or decreases due to a change in environmental temperature, the change in the closing time of the door increases.

Next, a description will be given of test results in which the relationship between the environmental temperature and the closing time of the door is obtained by using the adjusting valve manufactured based on the actual manufacturing dimensions.

[0048]

[Table 1]

Table 1 shows that the maximum depth of the V-shaped groove is 1.7 mm.
And the maximum depth of the V-shaped groove is 2.25.
mm of the present invention is attached to the door closer, and when the ambient temperature is 20 ° C., the regulating valve is set so that the closing time of the door is 5 seconds.
The result of having measured the value of the closing time when changing to ° C, 0 ° C, 10 ° C and 35 ° C is shown.

As a measuring method, the door to which the door closer was attached was left in a constant temperature room at each temperature for 2 hours, and then the closing time was measured.

As is clear from Table 1, the closing time at −10 ° C. is 11 seconds, whereas the closing time at −10 ° C. is 11 seconds, while the reference time of the ambient temperature is 20 ° C.
In the case of the present invention, it is 7.2 seconds, which is represented by a ratio of 1: 2.2 in the conventional case, whereas it is 1: 1.44 in the case of the present invention. This indicates that the ratio has decreased, making it less susceptible to changes in environmental temperature.

With respect to other temperatures, it can be seen that the change of the closing time is smaller in the case of the present invention, respectively.

[0053]

[Table 2]

Table 2 shows the result of measuring the value of the closing time when the environmental temperature changes after setting the regulating valve so that the closing time of the door is 6 seconds when the environmental temperature is 20 ° C. Is shown.

In this case, the closing time at -10 ° C. is 13.2 seconds for the conventional one, whereas the closing time at -10 ° C. is 9.2 for the closing time at 20 ° C. 4 seconds.

It can also be seen that, for other temperatures, the closing time is shorter in the case of the present invention.

FIG. 9 is a graph in which the measured values are plotted in Table 1 and Table 2 with the abscissa indicating the environmental temperature and the ordinate indicating the door closing time. Symbols a, b, c and d in FIG. 2 correspond to the reference numerals given to the curves in FIG.

In FIG. 9, the maximum depth of the V-shaped groove is 2.
The curve of this invention (b and d) which is 25 mm is
Compared to the conventional curve (a and c) having a maximum depth of 1.7, the curve is nearly horizontal, and it is obvious that the curve is hardly affected by the environmental temperature change.

According to the present invention, it is assumed that as the maximum depth of the V-shaped groove 31 becomes deeper, the influence of the environmental temperature change on the closing time of the door becomes smaller.

However, if the maximum depth of the V-shaped groove 31 is too large, there arises a problem that the strength of the spool shaft 32 is impaired.

Therefore, it is appropriate to keep the maximum depth of the V-shaped groove 31 at the dimension of the radius of the spool shaft or slightly larger than this dimension.

[0062]

According to the control valve of the present invention described above, the depth of the V-shaped groove of a conventionally used control valve can be simply increased by increasing the depth of the control valve. The effect can be reduced, and a remarkable effect can be obtained in use.

Further, in implementing the present invention, there is an advantage that the structure of the conventional regulating valve is not changed and there is no change in the manufacturing cost.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a cylinder cap provided with an adjustment valve of the present invention.

FIG. 2 is a diagram for explaining pipe friction resistance.

FIG. 3 is a diagram for explaining the resistance of a sudden change section.

FIG. 4 is a sectional view showing an opening of a suddenly changing section.

FIG. 5 is a longitudinal sectional view of a V-shaped groove of the regulating valve of the present invention.

FIG. 6 is an end view showing a tip of a spool shaft of the regulating valve of the present invention.

FIG. 7 is a longitudinal sectional view of a V-shaped groove of a conventionally used adjusting valve.

FIG. 8 is an end view showing a distal end of a spool shaft of a conventionally used adjusting valve.

FIG. 9 is a graph showing a relationship between an environmental temperature and a door closing time in a comparison test between a conventionally used regulating valve and the regulating valve of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Cylinder cap 20 Housing 22 Filter 23 Spool bearing 23a End face 24 Spool hole 25 Screw hole 26 Storage hole 30 Adjustment shaft 31 V-shaped groove 32 Spool shaft 32a Tip surface

Claims (1)

[Claims] 1. A spool shaft having a V-shaped groove formed along the generatrix at the shaft tip portion, the V-shaped groove having the deepest depth at the shaft end position and becoming linearly shallower toward the base of the shaft, and fitted to the spool shaft. A dashpot type adjusting valve comprising a spool bearing that is fitted with the dashpot type adjusting valve, wherein the depth of the V-shaped groove at the spool shaft end position is set to be equal to or larger than the radius of the spool shaft.