JPH06297399A - Water jet device - Google Patents

Abstract

PURPOSE:To improve the convergence performance of water and the cutting performance by increasing the viscosity of water by installing a cooling means for cooling the water supplied to a nozzle part for jetting the superhigh pressure cutting water to a prescribed temperature or below. CONSTITUTION:A water jet nozzle 1 has an injection port part 1a on the top edge side, and a high pressure chamber tube part 1c is installed integrally through an orifice part 1b on the rear edge side for the injection port part 1a, and a superhigh pressure water pipe 2 is connected with the high pressure chamber tube part 1c. The upstream edge 2a of the high pressure water pipe 2 is communication-connected with two pairs of high pressure side discharge edge part 4b through each check valve 5 of a booster 4 through an accumulator 3, and a cooling means 6 is installed on the downstream side of the accumulator 3. The cooling means 6 is equipped with an evaporator 13 in a cooling chamber 12 formed by fitting a heat insulating case body 11 on the outer periphery of the superhigh pressure water pipe 2 and the superhigh pressure water is cooled efficiently by the circulation of the coolant in the evaporator 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water jet device.

[0002]

2. Description of the Related Art Recently, attempts have been made to utilize the erosion action of water jets as a processing technique. Further, attention is paid to the advantages peculiar to the water jet as compared with conventional general processing methods, and it is expected to be applied to many fields such as special processing, high-pressure cleaning, construction, and medical technology.

By the way, in order to enhance the erosion action (particularly the cutting performance) of this water jet and to make it highly accurate, it is necessary to make the jet flow itself convergent and stable. And for that purpose, the following points are important.

1) It suppresses turbulence and deviation of the flow in the nozzle.

2) The fluctuation of the jet surface is reduced to delay the collapse and droplet formation of the jet as much as possible.

Therefore, as one of the methods for improving the convergence of the jet of the water jet and improving the cutting performance, for example, a method in which a polymer solution (polymer) is mixed into the cutting water to increase the viscosity of the water is conventionally used. Is known (see, for example, the Japan Society of Mechanical Engineers (B), Volume 56, No. 521: "Local structure of water jet and erosion mechanism of metallic material", issued October 1, 1989).

Since the aqueous polymer solution has a higher viscosity than water, turbulence and drift in the pipe tend to converge and a stable jet flow can be obtained as compared with the case where only water is used.
It also has the effect of delaying the formation of droplets on the jet surface.

[0008]

However, for that purpose, a device for mixing and supplying the polymer solution and water at a constant ratio is required, and the polymer solution used in the above-mentioned prior art is disposable. There is a problem that the waste liquid treatment is required. Further, this system has a drawback that the cost of the device for adjusting the solution and its concentration is high.
Also, it cannot be used in the food industry.

[0009]

The inventions described in each of claims 1 to 5 of the present application have been made for the purpose of solving the above problems, and are configured as follows. .

(1) Structure of the Invention According to Claim 1 In the water jet apparatus of the present invention, a nozzle portion, high-pressure water piping for supplying high-pressure water to the nozzle portion, and water from a water supply source to the high pressure In a water jet apparatus including a pressure booster that supplies high-pressure water to a water pipe, a cooling means for cooling the water supplied to the nozzle portion to a predetermined temperature or lower is provided.

(2) Structure of the Invention According to Claim 2 The water jet apparatus of the invention is based on the structure of the invention according to claim 1, and the cooling means in the structure is provided in the middle of the high-pressure water pipe. It is characterized by being.

(3) Configuration of the Invention According to Claim 3 The water jet apparatus according to the invention is based on the configuration of the invention according to claim 1, and the cooling means in the configuration has the pressure booster and the water supply source. It is characterized by being provided between.

(4) Structure of the Invention According to Claim 4 The water jet apparatus according to the invention is based on the structure of the invention according to claim 1, wherein the cooling means has the same structure as the high pressure water pipe. It is characterized by comprising two sets of cooling means, a first cooling means provided and a second cooling means provided between the pressure booster and the water supply source.

(5) Structure of the Invention According to Claim 5 The water jet device of the invention is based on the structure of the invention according to claim 4, and in the same structure, it is introduced from the water supply source to the second cooling means. Temperature sensor for detecting the temperature of the water to be supplied, and controlling the cooling capacity of the second cooling means in accordance with the temperature of the water detected by the temperature sensor to keep the temperature of the water supplied to the pressure booster constant at all times. It is characterized in that a water temperature control means for keeping the temperature is provided.

[0015]

The water jet apparatus of the invention described in each of claims 1 to 5 of the present application has the following operations corresponding to the above configurations.

(1) Operation of the invention according to claim 1 In the water jet apparatus of the present invention, the nozzle portion, the high-pressure water pipe for supplying high-pressure water to the nozzle portion, and the water from the water supply source In a water jet device including a pressure booster that supplies high-pressure water to a water pipe, a cooling unit that cools the water supplied to the nozzle unit to a predetermined temperature or less is provided, and the viscosity of water depends on the temperature. By utilizing this, the high-pressure cutting water after pressure increase by the pressure intensifier is cooled by the cooling means to increase viscosity and improve convergence.

(2) Operation of the invention according to claim 2 In the water jet apparatus of the invention, based on the structure of the invention according to claim 1, the cooling means in the structure is provided in the middle of the high-pressure water pipe. The high-pressure water, which has been pressurized by the pressure booster, is cooled to improve the viscosity and improve the convergence.

(3) Operation of the invention according to claim 3 In the water jet apparatus according to the invention, the structure of the invention according to claim 1 is basically used, and the cooling means in the structure has the pressure booster and the water supply source. The low pressure water before being pressurized by the pressure booster is cooled by the cooling means to increase the viscosity of the water.

(4) Operation of the invention of claim 4 In the water jet apparatus of the invention, the structure of the invention of claim 1 is basically used, and the cooling means in the structure is in the middle of the high-pressure water pipe. Disconnection from the water supply source due to a change in external temperature, which is composed of two sets of cooling means, a first cooling means provided and a second cooling means provided between the pressure booster and the water supply source. The temperature of the high-pressure water to the nozzle is lowered in consideration of the temperature change of water and the amount of temperature rise due to the compression work in the pressure intensifier to efficiently increase the viscosity.

(5) Operation of the invention of claim 5 The water jet apparatus of the invention is based on the structure of the invention of claim 4, and in the same structure, is introduced from the water supply source to the second cooling means. Temperature sensor for detecting the temperature of the water to be supplied, and controlling the cooling capacity of the second cooling means in accordance with the temperature of the water detected by the temperature sensor to keep the temperature of the water supplied to the pressure booster constant at all times. The water temperature control means for maintaining the temperature is provided so that cutting water having a constant temperature can always be supplied to the pressure booster.

Therefore, regardless of the temperature change of the cutting water from the water supply source, a constant viscosity and a constant convergence can be always maintained, and a constant cutting performance can be maintained.

[0022]

As described above, according to the present invention, by utilizing the fact that the viscosity of water depends on the temperature, the viscosity is increased by cooling the high pressure cutting water after pressure increase by the pressure intensifier by the cooling means. As a result of improving the convergence of the water jet, a thin and stable jet can be obtained, and its cutting performance (cutting depth, cutting margin, cutting surface accuracy, etc.) is improved. improves.

[0023]

【Example】

(1) First Embodiment FIGS. 1 and 2 show the configuration of a water jet apparatus according to a first embodiment of the present invention.

First, FIG. 1 shows the overall structure of the apparatus, and reference numeral 1 is a water jet nozzle (hereinafter, simply referred to as a nozzle). The nozzle 1 has a nozzle part 1a on the tip side and is integrally formed with a high pressure chamber tube part 1c via an orifice part 1b on the rear end side with respect to the nozzle part 1a. Is connected to the downstream end 2b of the ultra high pressure water pipe 2 in a communicating state.

Then, the nozzle 1 first guides the ultrahigh pressure water supplied through the ultrahigh pressure water pipe 2 into the high pressure chamber tube portion 1c, and then converges the ultrahigh pressure water at the orifice portion 1b to change the flow velocity. It is made to rise and is made into a jet from the jet portion 1a to be jetted.

The upstream end 2a of the ultra high pressure water pipe 2 is connected to each of the check valves 5 and 5 of the pressure booster 4 via the accumulator 3.
An ultra-high pressure water cooling means 6 described later is provided downstream of the accumulator 3 while being connected to the two sets of high pressure side discharge ends 4b, 4b via the.

The pressure booster 4 has two sets of low pressure side suction end portions 4.
The a and 4a are connected to the discharge side end portion 8b of the water feed pump 8 through check valves 7 and 7, respectively. The water supply pump 8 is
The suction side end portion 8a is connected to the water supply source 9 so as to communicate therewith,
Water is sucked from a water supply source 9 and supplied to the pressure booster 4 via check valves 7 and 7.

The pressure booster 4 is driven by a hydraulic pump 10 to increase the pressure of water supplied from the water supply pump 8 and then cools it from the accumulator 3 via the cooling means 6 and then to the nozzle 1. Supply at ultra-high pressure.

For example, as shown in FIG. 2, the cooling means 6 forms a cooling chamber 12 inside by fitting a heat insulating housing 11 made of a heat insulating material to the outer circumference of the ultra high pressure water pipe 2 and cooling the same. By providing an evaporator 13 in the chamber 12 and supplying and circulating a cooling refrigerant from the outside to the evaporator 13, it is possible to efficiently cool the ultra-high pressure water flowing through the ultra-high pressure water pipe 2. ing.

In general, the viscosity of water is inversely proportional to its temperature, and the cutting depth of the water jet of the water jet is proportional to the viscosity of the water, as is clear from the characteristics shown in FIG.

Therefore, as described above, when the temperature of the ultra-high pressure water supplied to the nozzle 1 is lowered to the optimum temperature by the cooling means 6 to improve the viscosity, it is jetted from the nozzle portion 1a of the nozzle 1. The converging property of the jet (water jet) to be generated is improved, the jet diameter is reduced, and the cutting performance (cutting depth, cutting margin, cutting surface accuracy) is improved.

Now, for example, in the case of water, the water temperature when pressurized to 300 MPa rises to about 40.degree. At this time, the viscosity is 8.97e-4 [Pa · s]. When this is cooled to 3 ° C, the viscosity is 1.70e-3 [Pa · s], which is about twice as large.

For this reason, the flow is rectified in the nozzle tube earlier, and the convergence is improved. As a result, the cutting depth becomes deeper, the width of the cutting groove becomes narrower, and the cutting surface becomes smoother. is there. FIG. 8 shows the effect of the present invention estimated from a cutting experiment result when a polymer solution is added, and an improvement of about 8% in cutting depth can be expected. In FIG. 8, the cutting depth when the temperature of water is 40 ° C. is 100, and the change of the cutting depth when the temperature of water is changed is shown as a relative ratio (%).

As a secondary effect, application to processed foods such as frozen foods where the influence of heat is extremely disliked can be considered.

(2) Second Embodiment The cooling means 6 in the first embodiment may be constructed as shown in FIG. 3 as a second embodiment, for example.

In the cooling means 6 of this embodiment, cold water (brine) is directly circulated from the external chiller or the like into the cooling chamber 12 of the heat insulating housing 11 similar to that of the first embodiment so that the inside of the ultra high pressure water pipe 2 is circulated. It is characterized in that the ultra-high pressure water flowing through is cooled.

Even with the cooling means 6 having such a configuration, it is possible to obtain the same effect as that of the first embodiment.

(3) Third Embodiment Further, the cooling means 6 in the first embodiment can be constructed as shown in FIG. 4 as a third embodiment, for example.

The cooling means 6 of this embodiment forms a vacuum chamber inside the cooling chamber 12 of the heat insulating casing 11 similar to that of the first embodiment, and an expansion valve 14 is provided from the outside into the vacuum cooling chamber 11. An evaporator (vapor compression refrigerator) is configured by supplying water, and the steam evaporated in the cooling chamber 11 is exhausted to the outside via the vacuum suction means 15 to form a super high pressure water pipe. It is characterized in that the ultra-high pressure water flowing in 2 is cooled.

With the cooling means 6 having such a structure, it is possible to obtain the same effect as that of the first embodiment.

(4) Fourth Embodiment Further, the cooling means 6 in the third embodiment evaporates the water supplied from the water supply pump 8 to the cooling chamber 11 as shown in FIG. 5 as the fourth embodiment. It can also be configured to be used as a refrigerant.

That is, in the cooling means 6 of this embodiment, the water supplied from the water supply pump 8 (not the discharge pressure) is supplied to the vacuum cooling chamber 12 in the heat insulating casing 11 similar to that of the third embodiment, not from the outside. (About 1 MPa) is introduced and evaporated through the ejector capacity adjusting valve 16 and the expansion valve 17, and the steam evaporated in the cooling chamber 11 is driven by the ejector vacuum pump 18 driven by the discharge pressure of the water supply pump 8. It is characterized in that the ultra high pressure water flowing in the ultra high pressure water pipe 2 is cooled by being discharged to the outside through the pipe.

Even with the cooling means 6 having such a configuration, it is possible to obtain the same effect as that of the first embodiment. In particular, in the case of this configuration, since water is introduced as the evaporative refrigerant from the water supply pump 8 into the expansion valve 17 via the ejector capacity adjusting valve 16, there is an advantage that it is not necessary to separately provide an external water supply source. At the same time, it becomes possible to control the ultra high pressure water cooling temperature, and it becomes possible to set the cutting performance according to the application (workpiece).

(5) Fifth Embodiment Further, in the case where the cooling means 6 of the cold water (brine) supply type as in the second embodiment is constructed, for example, the fifth embodiment
As an embodiment, as shown in FIG. 6, the cold water (brine) may be supplied to an oil cooler 20 provided in the hydraulic pump 10 for driving the pressure booster to cool the oil.

If such a construction is adopted, in addition to the same effects as the second embodiment, at the same time the hydraulic pump 10
The oil cooling action can be obtained.

(6) Sixth Embodiment Next, FIG. 7 shows the water supply pump 8 and the pressure booster 4 in addition to the first cooling means 6A in the first to fifth embodiments.
A second cooling means 6B is provided between them so that the temperature of the water supplied to the pressure booster 4 is constantly kept at a constant temperature, and then the temperature of the ultra-high pressure water is again kept at a constant value. The structure of the water jet apparatus which concerns on the 6th Example of this is shown.

In this embodiment, the first cooling means 6A provided in the middle of the super high pressure water pipe 2 similar to the ones in the constructions of the first to fifth embodiments is the cutting water introduced into the pressure booster 4. The temperature is set to be constant, and the capacity is set so as to reduce the temperature of the ultrahigh pressure water after the pressure increase to a constant value in consideration of the temperature rise amount of the ultrahigh pressure water due to the compression work of the pressure intensifier 4. ,
Moreover, the second cooling means 6B on the side of the water supply source supplies water to the nozzle 1 by keeping the temperature of the water sucked into the pressure booster 4 always constant regardless of the change of the water supply temperature due to the change of the external temperature. It is characterized in that the temperature of the ultra-high pressure water is kept constant to ensure a constant cutting performance.

That is, if the pressure conditions are the same, the temperature rise due to the compression work of the pressure booster 4 is almost constant, whereas the water temperature of the water supplied from the water supply source 9 fluctuates due to external factors such as the air temperature. Therefore, the cutting capacity is not changed by changing the amount of heat exchange in the second cooling means 6B according to the water temperature of the supplied water to keep the temperature of the water entering the pressure booster 4 constant. The heat exchange capacity of the first cooling means 6A is constant.

For the temperature control, for example, a water temperature sensor T for detecting the temperature of the cutting water from the water supply pump 8 to the second cooling means 6B is provided, and the water temperature sensor T constantly supplies the water supplied from the water supply source 9. Is detected and the controller 30 drives and controls the motor 21 for adjusting the opening degree of the cold water supply amount variable valve 19 for varying the cold water supply amount to the second cooling means 6B based on the detected temperature.

According to such a configuration, the above-mentioned first to fifth
In addition to the effects of the embodiment, it is possible to always maintain a constant cutting performance regardless of the water temperature of the water supply source 9.

[Brief description of drawings]

FIG. 1 is a system diagram showing an overall configuration of a water jet device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a configuration of ultrahigh pressure water cooling means of the same apparatus.

FIG. 3 is a sectional view showing a structure of a cooling means of a water jet apparatus according to a second embodiment of the present invention.

FIG. 4 is a sectional view showing a structure of a cooling means of a water jet device according to a third embodiment of the present invention.

FIG. 5 is a system diagram showing an overall configuration of a water jet device according to a fourth embodiment of the present invention.

FIG. 6 is a system diagram showing an overall configuration of a water jet device according to a fifth embodiment of the present invention.

FIG. 7 is a system diagram showing an overall configuration of a water jet device according to a sixth embodiment of the present invention.

FIG. 8 is a characteristic diagram showing the relationship between the viscosity of water by a water jet jet and the cutting performance in each of the above examples.

[Explanation of symbols]

1 is a nozzle, 1a is a nozzle, 1b is an orifice, 1c is a high pressure chamber tube, 3 is an accumulator, 4 is a pressure booster,
6 is a cooling means, 6A is a first cooling means, 6B is a second cooling means, 20 is an oil cooler, 30 is a controller, T
Is a water temperature sensor.

Claims (5)

[Claims] 1. A water jet comprising a nozzle section, a high-pressure water pipe for supplying high-pressure water to the nozzle section, and a pressure intensifier for supplying water from a water supply source to the high-pressure water pipe after high-pressure supply. A water jet device, wherein the device is provided with a cooling means for cooling the water supplied to the nozzle portion to a predetermined temperature or lower. 2. The water jet apparatus according to claim 1, wherein the cooling means is provided in the middle of the high pressure water pipe. 3. The water jet apparatus according to claim 1, wherein the cooling means is provided between the pressure booster and a water supply source. 4. The cooling means comprises two sets of cooling, a first cooling means provided in the middle of the high-pressure water pipe and a second cooling means provided between the pressure booster and the water supply source. The water jet apparatus according to claim 1, further comprising means. 5. A temperature sensor for detecting the temperature of water introduced from the water supply source to the second cooling means, and the cooling capacity of the second cooling means is controlled according to the water temperature detected by the temperature sensor. The water jet apparatus according to claim 4, further comprising: a water temperature control unit that keeps the temperature of the water supplied to the pressure booster constant at all times.